Electronic characteristics of thin-film CdS-CdTe photovoltaic cells
Abstract
Diode characteristics of the backwall CdS/CdTe cell are studied. Diode parameters are alpha = 18.1/V and J0 = 5.1 x 10 to the -9th A/sq cm in the dark. The characteristic is substantially different under illumination. Measurements of short-circuit current as a function of light intensity and spectral response as a function of bias voltage indicate that collection efficiency is dependent on the junction field and interface recombination. The electron-beam-induced current is not a simple exponential function of the distance from the junction. A junction transport model which includes interface recombination and tunneling is presented. Calculated diode characteristics from this model match the experimental characteristics for alpha = 18/V, J0 = 14 x 10 to the -9th A/sq cm, interface-state density = 0.54 x 10 to the 11th/sq cm and electron mobility = 4 sq cm/V-s at the junction. Voltage-dependent loss of the light-generated electrons by trapping at the interface states appears to be the major cause of the differences in the diode characteristics both in the dark and under illumination.
- Publication:
-
19th IEEE Photovoltaic Specialists Conference
- Pub Date:
- 1987
- Bibcode:
- 1987pvsp.conf..216S
- Keywords:
-
- Cadmium Sulfides;
- Cadmium Tellurides;
- Heterojunctions;
- Photovoltaic Cells;
- Thin Films;
- Volt-Ampere Characteristics;
- Electron Beams;
- Electron Mobility;
- Open Circuit Voltage;
- Short Circuit Currents;
- Electronics and Electrical Engineering