TemperatureDependent Transient Capacitance in In Ga AsIn Pbased

Temperature-Dependent Transient Capacitance in In. Ga. As/In. P-based Diodes Kiril Simov and Tim Gfroerer Davidson College Mark Wanlass NREL Supported by the American Chemical Society – Petroleum Research Fund

Motivation: Thermophotovoltaics Thermal Radiation Heat Source Blackbody Radiator Blackbody Radiation Photovoltaic Cell

Experimental Setup Computer with Lab. VIEW (5) Digital Scope (Tektronix) Capacitance meter (Boonton) (4) Cryostat with sample (1) (2) 77 K (3) Oxford Agilent Temp Controller Pulse Generator

P-N Junction Depletion Layer with Bias Depletion Layer + + + + + P + + + + + - + + Depletion Layer - N - With Bias

Typical Capture Data – Dependence on Pulse Length

Capture Analysis Capture cross-section Holes: s = 2. 5 x 10 -20 cm 2 Electrons: s = 7. 5 x 10 -21 cm 2

Number of Traps ~ 7 x 1015 cm-3

D Typical Escape data – Dependence on Temperature

Escape Analysis ~ trap depth

Conclusions n n n A deep level has been detected The effective trap cross-section is ~10 -20 cm 2 The trap concentration is ~ 1016 cm-3 The depth of the level is ~ 0. 30 e. V Our results are consistent with sub-bandgap PL from similar structures. Web links: This talk: http: //webphysics. davidson. edu/faculty/thg/talksposters/MAR-04. ppt PL poster: http: //webphysics. davidson. edu/faculty/thg/talksposters/SESAPS-03. ppt

Device Structure p+ layer junction n layer