CHARACTERIZATION OF A-GE-H WITH THE STEADY-STATE PHOTOCARRIER GRATINGMEASUREMENT

The steady state photocarrier grating measurement technique has been u sed and is shown to be valid for the characterization of steady-state transport properties of minority carriers in undoped improved quality hydrogenated amorphous germanium (a-Ge:H). Deviations from the theoret ically predicted behavior of the measurement have been observed on som e a-Ge:H samples. At room temperature in a-Ge:H, the ratio of photocon ductivity to dark conductivity is less than 1. The high density of the rmally generated carrier is observed to affect the measurement by redu cing its sensitivity. Whether it is also the cause of the observed dev iation will be discussed.