temperature-dependent transient capacitance in ingaas/inp-based diodes
DESCRIPTION
Temperature-Dependent Transient Capacitance in InGaAs/InP-based Diodes. Kiril Simov and Tim Gfroerer Davidson College Mark Wanlass NREL Supported by the American Chemical Society – Petroleum Research Fund. Thermal Radiation. Blackbody Radiation. Photovoltaic Cell. Heat Source. - PowerPoint PPT PresentationTRANSCRIPT
Temperature-Dependent Transient Capacitance in InGaAs/InP-based Diodes
Kiril Simov and Tim GfroererDavidson CollegeMark Wanlass
NRELSupported by the American Chemical Society – Petroleum Research Fund
Motivation: Thermophotovoltaics
Photovoltaic
CellHeat Source
Blackbody Radiator
ThermalRadiation Blackbody
Radiation
Experimental SetupComputer with LabVIEW
Temp Controller
Pulse GeneratorCryostat with sample
Digital Scope(Tektronix)
(1)(2)
(3)
(4)
(5)
Oxford77K
Agilent
Capacitance meter (Boonton)
P-N Junction Depletion Layer with Bias
Depletion Layer With Bias
Depletion Layer
-
-
-
+
+
+
P N+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
++
+
+
+
-
--
-
-
Typical Capture Data –Dependence on Pulse Length
-200 0 200 400 600 800
1E-3
0.01
0.1
Temp: 77KPulse Length:
10 s 30 s 100 s 200 s
Cap
acita
nce
Cha
nge
(a.u
.)
Time (s)
Capture Analysis
0 200 400 600-8
-7
-6
-5
-4
-3
avg
=111 +/- 2 s
T = 77K, Bias:-0.1V steady state-0.3V reverse bias
blue
= 109 s
red
=113 s
Ln (A
mpl
itude
of T
rans
ient
) (a
.u.)
Pulse Length (us)
DNv
1
Holes: = 2.5 x 10-20 cm2
Electrons: = 7.5 x 10-21
cm2
Capture cross-section
-400 0 400 800 1200 1600
0.0
0.1
0.2
0.3
0.4Temp: 77K
700s pulse Exp Fit
Cfree
Ctrapped
Cap
acita
nce
Cha
nge
(a.u
.)
Time (s)
Number of Traps
DF
TT N
CCN
~ 7 x 1015 cm-3
Typical Escape data – Dependence on Temperature
-100 0 100 200 300 400 500 600 700 800
-9
-6
-3
0
= 33 s = 51 s
= 123 s
Ln
( C
) (
a.u.
)
Time(s)
77K 146K 156K
Escape Analysis
~ trap depth
75 80 85 90 954
6
8
10
12
Avg Ea: 0.30 +/- 0.02 eV
Escape Rate ~ A * e-Ea / kT
Ln (E
scap
e R
ate)
(s-1)
Energy 1/kT (eV-1)
Bias ~ 0V -1V -2V
Conclusions A deep level has been detected The effective trap cross-section is ~10-20 cm2
The trap concentration is ~ 1016 cm-3
The depth of the level is ~ 0.30 eV Our results are consistent with sub-bandgap PL
from similar structures. Web links:
This talk: http://webphysics.davidson.edu/faculty/thg/talks-posters/MAR-04.pptPL poster: http://webphysics.davidson.edu/faculty/thg/talks-posters/SESAPS-03.ppt
Device Structure
p+ layer
n layerjunction