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Temperature-DependentGateBiasStressEffectinDioctylbenzothieno[2,3-b]benzothiophene-BasedThin-FilmTransistor

ArticleinIEEETransactionsonElectronDevices·March2017

DOI:10.1109/TED.2017.2670020

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TianjunLiu

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ChaoJiang

NationalCenterforNanoscienceandTechnology

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IEEE TRANSACTIONS ON ELECTRON DEVICES 1

Temperature-Dependent Gate Bias Stress Effectin Dioctylbenzothieno[2,3-b]benzothiophene-

Based Thin-Film TransistorJiawei Wang, Tianjun Liu, Yiwei Zhang, and Chao Jiang

Abstract— We carried out a systematic researchon temperature-dependent bias stress instability forDioctylbenzothieno[2,3-b]benzothiophene-based organicthin-film transistors (OTFTs) below 200 K. 2-D grainsboundaries model was employed to analyze the correlationbetween bias stress effects and the morphologies of firstmonolayer of the organic film. This enabled us to studythe contribution to the shifts of threshold voltage fromboth grain boundaries and grains/dielectric interface byanalyzing the temperature-dependent electrical properties.This paper may deepen our understanding of the biasstress induced threshold voltage shifts influenced bymicrostructures of the active layer and be helpful to theoptimization the designation of poly-crystalline OTFTs.

Index Terms— Bias stress effect (BSE), chargetransport, organic thin-film transistor (OTFT), temperaturedependence.

I. INTRODUCTION

ORGANIC thin-film transistor (OTFT), as a fundamentalcomponent in application of organic logical circuits,has been extensively studied for decades [1], [2]. Significantefforts have been made to optimize the OTFTs’ electricalperformances, and the charge carrier mobilities have reachedvalues larger than 10 cm2V−1s−1 [3], much better than theirα-Si:H TFT counterparts. However, the reliability of OTFTs,influenced by organic materials’ degradation, repeating dutycircles, and longtime gate bias stress, is not adequate forspecific application. Bias stress effect (BSE), a phenomenonthat threshold voltage shifts to the applied gate bias voltage,is a vital issue of the OTFT’s operational instability [4], [5].The origins of BSE have been generally attributed to charge

Manuscript received February 4, 2017; accepted February 13, 2017.This work was supported in part by the National Natural ScienceFoundation of China under Grant 11374070, Grant 61327009, andGrant 21432005 and in part by the Strategic Priority Research Program ofthe Chinese Academy of Sciences under Grant XDA 09040201. Thereview of this paper was arranged by Editor I. Kymissis. (Correspondingauthor: Chao Jiang.)

J. Wang is with the CAS Key Laboratory for Standardization and Mea-surement for Nanotechnology, Center of Excellence for Nanoscience,and National Center for Nanoscience and Technology, Beijing 100190,China, and also with University of Chinese Academy of Science,Beijing 100049, China.

T. Liu, Y. Zhang, and C. Jiang are with the CAS Key Laboratoryfor Standardization and Measurement for Nanotechnology, Center ofExcellence for Nanoscience, and National Center for Nanoscience andTechnology, Beijing 100190, China (e-mail: jiangch@nanoctr.cn).

Color versions of one or more of the figures in this paper are availableonline at http://ieeexplore.ieee.org.

Digital Object Identifier 10.1109/TED.2017.2670020

trapping in deep localized states [6], in which carriers couldhardly be released again within the time scale for chargetransport in OTFT. In the previous research works, variousfactors were suggested to introduce deep localized states intoOTFTs, including both intrinsic and extrinsic ones, such asbulk defects/impurities of active layer, localized states locatedwithin the interface and bulk of the dielectric layer, contactresistance, environmental conditions including light exposure,presence of moisture, and so on [6]. When it comes topolycrystalline OTFT, imperfect molecules arrangements ingrains boundaries (GBs) would to a great extent affect thedevices’ stability. Former works have been done concerningabout the relationship between the crystallinity of the organicactive layer and BSE in OTFTs [6]–[8].

One unique feature in OTFTs is that, under the gate elec-tric field, field induced carriers mainly distribute within afew nanometers with respect to the organic-dielectric inter-face [9], [10]. In our previous works [11]–[13], relationshipswere built up to analyze the correlation between electricalcharacteristics and the grains sizes in the first single molecularlayer of pentacene based OTFT. By employing a phenom-enological model involving 2-D single-layered grains andGBs [denoted as 2-D grain boundaries model (2DGB) in thefollowing], the impacts of GBs on device’s performance wereemphasized. And with this methods, deeper insights in to theBSE in polycrystalline OTFT. Based on the former works,in this paper, we reported a temperature-dependent BSE workon poly-crystalline OTFT based on organic small moleculeDioctylbenzothieno[2,3-b]benzothiophene (C8BTBT), whichmaterial exhibited potentials in fabricating thin-film transis-tors with considerable mobility[3], [14], [15]. We employedthe mentioned model 2DGB by separately considering thesingle-layered grains and GBs to investigate the BSE inpolycrystalline structured devices with treating the systemas heterogeneous. Specifically, the roles that GBs and otherregions (including grains together with dielectric layer) playin the devices’ reliability under prolonged gate stress werediscussed, comparing with treating the system homogeneously,2DGB provided more accurate and microscopic insight intothe carriers’ behaviors in operation instability of OTFTs.

II. EXPERIMENTAL

In the fabrication of OTFT devices, Heavily P-dopedsilicon wafers coated with thermally grown oxide layerof 300 nm acting as gate electrodes/substrates. Toluene solu-tion of polystyrene (PS) was spin-coated onto the substrate

0018-9383 © 2017 IEEE. Personal use is permitted, but republication/redistribution requires IEEE permission.See http://www.ieee.org/publications_standards/publications/rights/index.html for more information.

https://www.researchgate.net/publication/282044343_Grain_Size_and_Interface_Dependence_of_Bias_Stress_Stability_of_n-Type_Organic_Field_Effect_Transistors?el=1_x_8&enrichId=rgreq-1c32dd87fa8ba9b52deec67a5733058d-XXX&enrichSource=Y292ZXJQYWdlOzMxNDE2MjYzNztBUzo0NjgzOTM1Njk1OTEyOTZAMTQ4ODY4NTEzNzgxNw==https://www.researchgate.net/publication/268526862_Electrical_transport_mechanism_of_single_monolayer_pentacene_film_employing_field-effect_characterization?el=1_x_8&enrichId=rgreq-1c32dd87fa8ba9b52deec67a5733058d-XXX&enrichSource=Y292ZXJQYWdlOzMxNDE2MjYzNztBUzo0NjgzOTM1Njk1OTEyOTZAMTQ4ODY4NTEzNzgxNw==https://www.researchgate.net/publication/267495970_Facile_synthesis_of_highly_p-extended_heteroarenes_dinaphtho_2_3-b_2'_3'-f_chalcogenopheno_3_2-b_chalcogenophenes_and_their_application_to_field-effect_transistors?el=1_x_8&enrichId=rgreq-1c32dd87fa8ba9b52deec67a5733058d-XXX&enrichSource=Y292ZXJQYWdlOzMxNDE2MjYzNztBUzo0NjgzOTM1Njk1OTEyOTZAMTQ4ODY4NTEzNzgxNw==https://www.researchgate.net/publication/265169265_Two-dimensional_Quasi-Freestanding_Molecular_Crystals_for_High-Performance_Organic_Field-Effect_Transistors?el=1_x_8&enrichId=rgreq-1c32dd87fa8ba9b52deec67a5733058d-XXX&enrichSource=Y292ZXJQYWdlOzMxNDE2MjYzNztBUzo0NjgzOTM1Njk1OTEyOTZAMTQ4ODY4NTEzNzgxNw==https://www.researchgate.net/publication/265169265_Two-dimensional_Quasi-Freestanding_Molecular_Crystals_for_High-Performance_Organic_Field-Effect_Transistors?el=1_x_8&enrichId=rgreq-1c32dd87fa8ba9b52deec67a5733058d-XXX&enrichSource=Y292ZXJQYWdlOzMxNDE2MjYzNztBUzo0NjgzOTM1Njk1OTEyOTZAMTQ4ODY4NTEzNzgxNw==https://www.researchgate.net/publication/263951140_Charge_Transport_Model_Based_on_Single-Layered_Grains_and_Grain_Boundaries_for_Polycrystalline_Pentacene_Thin-Film_Transistors?el=1_x_8&enrichId=rgreq-1c32dd87fa8ba9b52deec67a5733058d-XXX&enrichSource=Y292ZXJQYWdlOzMxNDE2MjYzNztBUzo0NjgzOTM1Njk1OTEyOTZAMTQ4ODY4NTEzNzgxNw==https://www.researchgate.net/publication/234961327_Organic_small_molecule_field-effect_transistors_with_Cytop_TM_gate_dielectric_Eliminating_gate_bias_stress_effects?el=1_x_8&enrichId=rgreq-1c32dd87fa8ba9b52deec67a5733058d-XXX&enrichSource=Y292ZXJQYWdlOzMxNDE2MjYzNztBUzo0NjgzOTM1Njk1OTEyOTZAMTQ4ODY4NTEzNzgxNw==https://www.researchgate.net/publication/229781564_Reliability_of_Organic_Field-Effect_Transistors?el=1_x_8&enrichId=rgreq-1c32dd87fa8ba9b52deec67a5733058d-XXX&enrichSource=Y292ZXJQYWdlOzMxNDE2MjYzNztBUzo0NjgzOTM1Njk1OTEyOTZAMTQ4ODY4NTEzNzgxNw==https://www.researchgate.net/publication/229781564_Reliability_of_Organic_Field-Effect_Transistors?el=1_x_8&enrichId=rgreq-1c32dd87fa8ba9b52deec67a5733058d-XXX&enrichSource=Y292ZXJQYWdlOzMxNDE2MjYzNztBUzo0NjgzOTM1Njk1OTEyOTZAMTQ4ODY4NTEzNzgxNw==https://www.researchgate.net/publication/229781564_Reliability_of_Organic_Field-Effect_Transistors?el=1_x_8&enrichId=rgreq-1c32dd87fa8ba9b52deec67a5733058d-XXX&enrichSource=Y292ZXJQYWdlOzMxNDE2MjYzNztBUzo0NjgzOTM1Njk1OTEyOTZAMTQ4ODY4NTEzNzgxNw==https://www.researchgate.net/publication/223810846_Field-induced_mobility_degradation_in_pentacene_thin-film_transistors?el=1_x_8&enrichId=rgreq-1c32dd87fa8ba9b52deec67a5733058d-XXX&enrichSource=Y292ZXJQYWdlOzMxNDE2MjYzNztBUzo0NjgzOTM1Njk1OTEyOTZAMTQ4ODY4NTEzNzgxNw==https://www.researchgate.net/publication/51208478_Solution-Crystallized_Organic_Field-Effect_Transistors_with_Charge-Acceptor_Layers_High-Mobility_and_Low-Threshold-Voltage_Operation_in_Air?el=1_x_8&enrichId=rgreq-1c32dd87fa8ba9b52deec67a5733058d-XXX&enrichSource=Y292ZXJQYWdlOzMxNDE2MjYzNztBUzo0NjgzOTM1Njk1OTEyOTZAMTQ4ODY4NTEzNzgxNw==https://www.researchgate.net/publication/41883735_Bias-induced_threshold_voltages_shifts_in_thin-film_organic_transistors?el=1_x_8&enrichId=rgreq-1c32dd87fa8ba9b52deec67a5733058d-XXX&enrichSource=Y292ZXJQYWdlOzMxNDE2MjYzNztBUzo0NjgzOTM1Njk1OTEyOTZAMTQ4ODY4NTEzNzgxNw==https://www.researchgate.net/publication/8480998_A_Large-Area_Flexible_Pressure_Sensor_Matrix_with_Organic_Field-Effect_Transistors_for_Artificial_Skin_Applications?el=1_x_8&enrichId=rgreq-1c32dd87fa8ba9b52deec67a5733058d-XXX&enrichSource=Y292ZXJQYWdlOzMxNDE2MjYzNztBUzo0NjgzOTM1Njk1OTEyOTZAMTQ4ODY4NTEzNzgxNw==https://www.researchgate.net/profile/Jiawei_Wang32?el=1_x_100&enrichId=rgreq-1c32dd87fa8ba9b52deec67a5733058d-XXX&enrichSource=Y292ZXJQYWdlOzMxNDE2MjYzNztBUzo0NjgzOTM1Njk1OTEyOTZAMTQ4ODY4NTEzNzgxNw==https://www.researchgate.net/profile/Chao_Jiang4?el=1_x_100&enrichId=rgreq-1c32dd87fa8ba9b52deec67a5733058d-XXX&enrichSource=Y292ZXJQYWdlOzMxNDE2MjYzNztBUzo0NjgzOTM1Njk1OTEyOTZAMTQ4ODY4NTEzNzgxNw==https://www.researchgate.net/profile/Tianjun_Liu?el=1_x_100&enrichId=rgreq-1c32dd87fa8ba9b52deec67a5733058d-XXX&enrichSource=Y292ZXJQYWdlOzMxNDE2MjYzNztBUzo0NjgzOTM1Njk1OTEyOTZAMTQ4ODY4NTEzNzgxNw==

This article has been accepted for inclusion in a future issue of this journal. Content is final as presented, with the exception of pagination.2 IEEE TRANSACTIONS ON ELECTRON DEVICES

as a modified layer with thickness of 70 nm, then 40 nmorganic small molecule semiconducting material C8BTBT(AldrichCo.), was vacuum thermally evaporated onto thesubstrates, calibrated and monitored by a quartz oscillator.Various deposition rates (0.014, 0.075, and 0.25 nm/s) wereobtained by employing different source temperature. 3 nmthick molybdenum oxide and 30 nm thick Au were depositedthrough shadow-mask on the top surface of the C8BTBT film,to form the source-drain electrodes with a channel lengthL = 100 μm and width W = 2000 μm. To investigate thegrain sizes at the initial layer of the C8BTBT film, 1.5 nmC8BTBT submonolayer film was deposited also with the threedifferent deposition rates mentioned above.

The morphologies of the C8BTBT films were characterizedusing a Dimension 3100 (BrukerCo.) atomic force micro-scope (AFM) at tapping mode. The BSE characteristics of thedevices were conducted using a Keithley 4200 semiconductoranalyzer and a vacuum four-probe station system (Lakeshore),the stress conditions were set the same for all the devices andtemperature points, with drain and source electrodes unbiased,applying gate–source voltage as a constant value Vgs = −80 V.We chose to characterize the devices below 200 K, in orderto exclude the influence of the supercool water. The residualwater molecules’ migration could evidently contribute to BSE,and only below 200 K, the impacts could be frozen [16]. Onedevice was characterized for one single temperature point andanother device was for next point. The threshold voltages Vt swere extracted by

Ilin = WL

COXμ(VG − VT )γ Vds. (1)The exponent γ is due to the gate voltage-dependent carriers’mobility [17], [18].

III. RESULTS AND DISCUSSION

We employed heterogeneous treatments for the system bydividing the film of the initial molecular layer into grains andGBs with exact space distribution. As shown in Fig. 1, thenucleation density can be extracted by analyzing morphologyof submonolayer of C8BTBT. The average length scales ofgrains can be obtained by the simple model of Voronoipolygons, as we employed in the former work on pentacene[12]. The extracted grain sizes were 790, 542, and 320 nm forthe layers with three mentioned deposition rates, respectively.

For a better discussion about the electrical performance,we emphasize two type of trap states: 1) shallow traps dis-tributed in the band tails, with no more than several tensof meV with respected to the extended states, among whichcharge transport could take place by multiple hopping, or bybeing thermally activated back to extended states and 2) deeptraps located far below (0.1 eV or deeper) the extended states.Carriers captured by deep traps could hardly be activatedwithin time scale of charge transport, i.e., the characteristictime for a carrier’s staying on a deep trap is much larger thanthat for a carrier’s transport across the channel. Therefore,shallow traps mainly affect the charge transport process, whiledeep traps dominantly influence the threshold voltage.

Fig. 1. 5 × 5 μm2 AFM images of C8BTBT submonolayer with threedeposition rates, R = 0.014, 0.075, and 0.25 nm/s (top row), andillustration of the grains sizes at the first monolayer with Voronoi polygonmodel (bottom row).

Fig. 2(a) shows the ideal uniformity of the devices fabricatedin one batch and the inset is the negligibly small gate leakagecurrents at 200 K. Fig. 2(b) shows linear region transfercharacteristics C8BTBT OTFT with active layer of depositionrate R = 0.014 nm/s before and after gate bias for 400–4000 s,at two limits temperature points, T = 180 and 100 K. Thethreshold voltages VT were extracted by fitting(1) with thetemperature/bias time-dependent transfer curves, the shift ofthreshold voltage �VT at different temperature and bias timewere extracted with respect to initial time. As illustrated inFig. 2(c), �VT of different bias times at various temperatureswere listed for devices with deposition rates R = 0.014 nm/sand R = 0.25 nm/s, respectively. Evidently, the OTFTs withhigher active layer deposition rate had larger �VT , indicatinglarger numbers of deep trap states related to higher density ofthe GBs. As temperature decreased, the amplitudes of the �VTbecome suppressed, a sign suggesting that the charge carriers’trapping process depended on thermal activation assistance.

The Vt shifts were then associated with the initiallayer’s micro-morphology by employing the 2DGB model.We assumed that the deep traps that induced the VTshift could be attributed into the following. First, the deeplocalized states existing within the GBs. Molecules arrange-ment is highly disordered in GBs, leading to localiza-tion of electronic states with high density of deep traps.The shift of threshold voltage induced by trapped chargeswithin this part is denoted as �VTGB. �VTGB is pro-portional to the effective area SGB and trapped carri-ers’ density nt : �VTGB = ((SGB · nt )/(Ci · W · L)) =((2LGB · nt · q)/((LG + LGB) · Ci )), where W and L are thetransistor’s channel width and length, LGB and LG is theaverage size scale of GB and grain, Ci is the capacitance ofthe dielectric per unit area. Next, the deep localized statesdistributed inside grain regions and within the PS layer. Theincidental impurity doping and the disorder in the dielectriccould both bring in about deep trap states. The shift ofthreshold voltage induced by trapped charges of these factorsis denoted as �VTGD. Then the total �VT can be expressed as

�VT = �VTGD + 2LGB · nt · q(LG + LGB) · Ci . (2)

https://www.researchgate.net/publication/311167227_Manipulating_Transistor_Operation_via_Nonuniformly_Distributed_Charges_in_a_Polymer_Insulating_Electret_Layer?el=1_x_8&enrichId=rgreq-1c32dd87fa8ba9b52deec67a5733058d-XXX&enrichSource=Y292ZXJQYWdlOzMxNDE2MjYzNztBUzo0NjgzOTM1Njk1OTEyOTZAMTQ4ODY4NTEzNzgxNw==https://www.researchgate.net/publication/269576513_General_Einstein_relation_model_in_disordered_organic_semiconductors_under_quasiequilibrium?el=1_x_8&enrichId=rgreq-1c32dd87fa8ba9b52deec67a5733058d-XXX&enrichSource=Y292ZXJQYWdlOzMxNDE2MjYzNztBUzo0NjgzOTM1Njk1OTEyOTZAMTQ4ODY4NTEzNzgxNw==https://www.researchgate.net/publication/260704854_Influence_of_grain_size_at_first_monolayer_on_bias-stress_effect_in_pentacene-based_thin_film_transistors?el=1_x_8&enrichId=rgreq-1c32dd87fa8ba9b52deec67a5733058d-XXX&enrichSource=Y292ZXJQYWdlOzMxNDE2MjYzNztBUzo0NjgzOTM1Njk1OTEyOTZAMTQ4ODY4NTEzNzgxNw==https://www.researchgate.net/publication/224405946_Transport_energy_in_organic_semiconductors_with_partially_filled_localized_states?el=1_x_8&enrichId=rgreq-1c32dd87fa8ba9b52deec67a5733058d-XXX&enrichSource=Y292ZXJQYWdlOzMxNDE2MjYzNztBUzo0NjgzOTM1Njk1OTEyOTZAMTQ4ODY4NTEzNzgxNw==

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Fig. 2. (a) Transfer curves of ten devices from one batch, the inset isthe gate leakage current at 200 K. (b) Transfer characteristics of OTFTswith deposition rates of 0.014 nm/s, for origin, and ten bias stress timepoints, at temperature points T = 180 and 100 K, respectively. (c) ΔVTversus gate bias stress time for OTFTs with deposition rates of 0.014 and0.25 nm/s, at three different temperatures.

As Fig. 3(a) shows, by fitting (2) with the experimentallyobtained �VT versus initial layer’s grain size, the fittingparameter LGB is obtained as 5.01 nm. At different biastime and different temperatures, the extracted trapped carriers’density nt within grains boundaries were 9.62 × 1012 cm−2,12.2 × 1012cm−2, 13.2 × 1012 cm−2, and 14.3 × 1012 cm−2,respectively, for t = 400, 1600, 2800, and 4000 s at 180 Kand the four values were 0.99×1012 cm−2, 1.18×1012 cm−2,1.44×1012 cm−2, and 1.65×1012 cm−2 at lower temperatureT = 100 K. This indicates that, at higher temperature,it is more likely for carriers being trapped by the deeplocalized states, corresponding with the value of �VT temper-ature dependence behavior. In addition, at lower temperatureT = 100 K, the �VT became less dependent on grains sizein the first monolayer than that at 180 K.

�VTGD and �VTGB were, respectively, obtained with (2).As shown in Fig. 3(b) and (c), evidently, �VTGB showed

Fig. 3. (a) Relationship between ΔVT and grain size for bias stresstimes of 400, 1600, 2800, and 4000 s, respectively, at T = 180 K,illustrated by experimental (symbols) fit with 2DGB model (lines). (b) and(c) Correspondence between ΔVTG and ΔVTGB with stress time. Insetof (c): plot of ΔVTG versus temperature.

similar behavior as the parameter nt , it became smaller at thesame bias stress time as temperature decreased. While �VTGbehaved somehow differently, changed less with temperature,and even showed weak negative correlation with temperature.Different temperature-dependent characters between �VTGDand �VTGB can be related to the different charge transportmechanisms. In another word, when the gate bias stressswitched ON, the carriers were injected into and accumulatedthe channel, without any drain–source biases, an injectedcarrier would mainly diffuse within the initial molecular layerrandomly, until being captured by a deep trap. Within the GBsregions, due to the disordered arrangements of the molecules,charge transport is dominated by thermal activated hopping

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Fig. 4. (a) ΔVT (symbols). (b) ΔVTGB (symbols) versus stress timeat T = 180, 140, and 100 K, respectively, fit with stretched exponentialrelationship given by expression 3.

among the shallow traps, the higher temperature leads to thehigher hopping rates and shorter time for being captured,leading to a thermal activated feature. While the trappingcharges that induced �VTGD should undergo different process.Here, what should be noted is that the gate leakage current isnegligible small, we propose that the charge trapping insidebulk of insulator layer could be neglected. In addition, if notso, �VTGD shown in Fig. 4(c) should feature a strong thermalactivation character resulting from the carriers motion in theinsulator layer [19]. So the deep traps that induced �VTGDwere assumed distributing inside the grains and within the PSinterface. Unlike the motions of those within GBs, the chargecarriers in grains would undergo less hopping among shallowtraps by moving more delocalized. By aid of suppressing thephonon’s scattering or polaronic effect [20], lower temperatureease the motion of the carriers.

The distinct behaviors between �VTGD and �VTGBemphasized the importance of heterogeneous treatment ofthe ploycrystalline system. To obtain a deeper insight,the time evolutions of �VT were investigated. Conventionally,the stretched exponential relationship developed for analyzingthe instability of a-Si TFT, given by [6]

�VT (t) = (VT (t = ∞) − VT (t = 0))(

1 − exp((

− tτ

)β))

(3)

has been generally applied in quantitative study of timeevolution of BSE in OTFTs. The expression describes the biasstress generated deep traps induced by the dangling bondsin α-Si TFT. And the rate of the generation of deep trapsis limited by the dispersive diffusion of hydrogens. Whichprocess features by an exponential distribution of trap energieswith characteristic energy kT0. And τ is the characteristictime for the process that a mobile charge carrier becomestrapped, the exponent β is a temperature-dependent parameter,β = T/T0.

We extracted the characteristic time τ for both �VTGB andthe total threshold voltage shift �VT , as shown in Fig. 4 (dataof devices with active layer deposited at rate 0.25 nm/s weredisplayed). The fitting values of τ for �VT were 0.44e7, 2.3e7,and 15.6e7 s, respectively, at 180, 140, and 100 K. While τfor �VTGB varied much more drastically with temperature,the values were 0.48e7, 21.5e7, and 2800e7 s. The larger valueof τ means longer time for charge trapping process, corre-sponding with slower carriers’ diffusive motions and leadingto device’s more stable behavior. As temperature decreased,the GB regions exhibited a more stable behavior with lesscontribution to the devices’ threshold instability, featuringmuch larger values of τ , this were attributed to the suppressionof carrier’s hopping diffusion among the shallow traps withinGBs before final captures. The values of parameter β extractedby (3) for �VT were 0.21, 0.22, and 0.21, whereas those of�VTGB were 0.217, 0.175, and 0.134. Although in disorderedorganic semiconductor, there are few possibilities for creationof defects (especially in our case as the migration of waterwas suppressed), the diffusion of carriers in exponential typedensity of shallow traps before being captured by deep trapscan also lead to a stretched exponential �VT ’s time-evolutionbehavior. As the situations of carriers’ diffusion and trappingprocesses in disordered GB regions, by excluding the thresholdvoltage shift contributed by ingrain and PS interface traps,�VTGB exhibited well-fitting with the stretched exponentialmodel, reasonable parameter T0 = 792 K (kT0 = 66 meV)was obtained, which was a typical value for exponential trapdensity of states in disorder organic semiconductor [21]. Andsmaller β at lower temperature results in very slower changein �VTGB, as shown in Fig. 4(b) is also a consequenceof the temperature-dependent carriers’ diffusion process ina specific exponential type band tail. Nevertheless, whentreating the polycrystalline system as uniform homogeneousmedia, although the total shift of threshold voltage �VTcan phenomenologically fit with expression 3, the extractedchangeless values of β were not reasonable with respect tothe relationship β = T/T0. The discrepancy should be due tothe hybrid behavior of the threshold voltage shifts contributedby multiple factors, of which �VTGB and �VTGD showeddistinct temperature dependence under gate bias stress asdemonstrated in this paper. The �VTGD’ dynamic behaviorwas not analyzed by the stretched exponential relationship,because the factors included are complex and the nonactivationtemperature dependence of �VTGD could not be modeledby (3). It is difficult to further decouple the charge trappingin defects of grains and the ones in the PS interface, but itshould be clear that, besides the diffusive carriers distributed

https://www.researchgate.net/publication/230580579_Analytic_model_of_hopping_mobility_at_large_charge_carrier_concentrations_in_disordered_organic_semiconductors_Polarons_versus_bare_charge_carriers?el=1_x_8&enrichId=rgreq-1c32dd87fa8ba9b52deec67a5733058d-XXX&enrichSource=Y292ZXJQYWdlOzMxNDE2MjYzNztBUzo0NjgzOTM1Njk1OTEyOTZAMTQ4ODY4NTEzNzgxNw==https://www.researchgate.net/publication/229781564_Reliability_of_Organic_Field-Effect_Transistors?el=1_x_8&enrichId=rgreq-1c32dd87fa8ba9b52deec67a5733058d-XXX&enrichSource=Y292ZXJQYWdlOzMxNDE2MjYzNztBUzo0NjgzOTM1Njk1OTEyOTZAMTQ4ODY4NTEzNzgxNw==

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within the GBs, the other main carriers that induced �VTGDshould locate in the grain regions, and these carriers were lessinfluenced by the shallow traps and featured more delocalizedmotion during the diffusion process before capture. Treatingthe poly-crystalline system as uniform and continuous mayprovide convenience for analyze the electrical performances,however, to gain a more accurate insight into the mechanism ofthe carriers’ behaviors, 2DGB provide a pathway to separatelystudy the roles played by GBs and other factors separately.

IV. CONCLUSION

In conclusion, 2DGB was employed to quantitativelydescribe the correlation between threshold voltage shift andgrain boundaries density at the first monolayer of the OTFT.The contribution to the shift of threshold voltages (�VT ) fromboth grains/dielectric interface (�VTGD) and grains bound-aries (�VTGB) were studied with analyzing the temperature-dependent electrical measurements. We found that �VTGDalmost unchanged or slightly increased with temperaturedecreasing, while �VTGB took on a thermal activation char-acter. These were correlated with carrier’s diffusion limitedcharge trapping process. And well fittings between �VTGBand stress time t by a stretched exponential model wereobtained with rather reasonable fitting parameters. This papermight offer a path way for obtaining more insights into themechanism of OTFTs’ operation instability.

REFERENCES

[1] R. A. Street, “Thin-film transistors,” Adv. Mater., vol. 21, no. 20,pp. 2007–2022, 2009.

[2] T. Someya, T. Sekitani, S. Iba, Y. Kato, H. Kawaguchi, and T. Sakurai,“A large-area, flexible pressure sensor matrix with organic field-effecttransistors for artificial skin applications,” Proc. Nat. Acad. Sci. USA,vol. 101, no. 27, pp. 9966–9970, 2004.

[3] D. He et al., “Two-dimensional quasi-freestanding molecular crystalsfor high-performance organic field-effect transistors,” Nature Commun.,vol. 5, pp. 5162–5168, Oct. 2014.

[4] H. L. Gomes et al., “Bias-induced threshold voltages shifts in thin-filmorganic transistors,” Appl. Phys. Lett., vol. 84, no. 16, pp. 3184–3187,2004.

[5] W. L. Kalb, T. Mathis, S. Haas, A. F. Stassen, and B. Batlogg, “Organicsmall molecule field-effect transistors with cytop gate dielectric: Elim-inating gate bias stress effects,” Appl. Phys. Lett., vol. 90, no. 9,pp. 092104-1–092104-3, 2007.

[6] H. Sirringhaus, “Reliability of organic field-effect transistors,” Adv.Mater., vol. 21, nos. 38–39, pp. 3859–3873, 2009.

[7] D. Li, E.-J. Borkent, R. Nortrup, H. Moon, H. Katz, and Z. Bao, “Humid-ity effect on electrical performance of organic thin-film transistors,”Appl. Phys. Lett., vol. 86, no. 4, p. 042105, Jan. 2005.

[8] R. Ahmed, C. Simbrunner, M. A. Baig, and H. Sitter, “Grain sizeand interface dependence of bias stress stability of n-type organicfield effect transistors,” ACS Appl. Mater. Interfaces, vol. 7, no. 40,pp. 22380–22384, 2015.

[9] M. Mottaghi and G. Horowitz, “Field-induced mobility degradationin pentacene thin-film transistors,” Organic Electron., vol. 7, no. 6,pp. 528–536, Dec. 2006.

[10] Y. Zhang et al., “Probing carrier transport and structure-property relationship of highly ordered organic semiconductorsat the two-dimensional limit,” Phys. Rev. Lett, vol. 116, no. 1,pp. 016602-1–016602-6, 2016.

[11] Y. Y. Hu, L. M. Wang, Q. Qi, D. X. Li, and C. Jiang, “Chargetransport model based on single-layered grains and grain boundariesfor polycrystalline pentacene thin-film transistors,” J. Phys. Chem. C,vol. 115, no. 47, pp. 23568–23573, 2011.

[12] Y. W. Zhang, D. X. Li, and C. Jiang, “Influence of grain size at firstmonolayer on bias-stress effect in pentacene-based thin film transistors,”Appl. Phys. Lett., vol. 103, no. 21, pp. 213304-1–213304-4, 2013.

[13] J. Wang and C. Jiang, “Electrical transport mechanism of single mono-layer pentacene film employing field-effect characterization,” OrganicElectron., vol. 16, pp. 164–170, Jan. 2015.

[14] T. Yamamoto and K. Takimiya, “Facile synthesis of highlyπ -extended heteroarenes dinaphtho[2,3-b:2′ ,3′- f ]chalcogenopheno[3,2-b]chalcogenophenes, and their application to field-effecttransistors,” J. Amre. Chem. Soc., vol. 129, no. 8, pp. 2224–2225,2007.

[15] J. Soeda et al., “Solution-crystallized organic field-effect transistorswith charge-acceptor layers: High-mobility and low-threshold-voltageoperation in air,” Adv. Mater., vol. 23, no. 29, pp. 3309–3314, 2011.

[16] L. Li, N. Lu, M. Liu, and H. Bässler, “General Einstein relation modelin disordered organic semiconductors under quasiequilibrium,” Phys.Rev. B, Condens. Matter, vol. 90, no. 21, p. 214107, 2014.

[17] L. Li, G. Meller, and H. Kosina, “Transport energy in organic semicon-ductors with partially filled localized states,” Appl. Phys. Lett., vol. 92,no. 1, pp. 013307-1–013307-3, 2008.

[18] L. Bu et al., “Manipulating transistor operation via nonuniformlydistributed charges in a polymer insulating electret layer,” Phys. Rev.Appl, vol. 6, no. 5, p. 054022, 2016.

[19] K. Hannewald, V. M. Stojanović, J. M. T. Schellekens, P. A. Bobbert,G. Kresse, and J. Hafner, “Theory of polaron bandwidth narrowing inorganic molecular crystals,” Phys. Rev. B, Condens. Matter, vol. 69,no. 7, p. 075211-7, 2004.

[20] I. I. Fishchuk, V. I. Arkhipov, A. Kadashchuk, P. Heremans, andH. Bässler, “Analytic model of hopping mobility at large chargecarrier concentrations in disordered organic semiconductors: Polaronsversus bare charge carriers,” Phys. Rev. B, Condens. Matter, vol. 76,pp. 045210-1–045210-12, Jul. 2007.

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