Ruhi Kaplan

Frequency-resolved photoconductivity in a-SiGe:H

Abstract Frequency-resolved photocurrent measurements were carried out on hydrogenated amorphous silicon–germanium (a-SiGe:H) thin film alloys between 20 and 290 K, by using the quadrature frequency-resolved spectroscopy method which yields lifetime distributions directly. The results show that the frequency-resolved photocurrent depends on excitation light intensity and temperature and thus they give information about recombination kinetics.

Frequency-resolved photocurrent studies of a-

Optically modulated photocurrent response of amorphous selenium (a-Se) thin films was measured between 20 K and 295 K, by using the in-quadrature frequency-resolved spectroscopy method. The results show that the modulated photocurrent depends on external parameters such as excitation light intensity and temperature, giving information about recombination kinetics.

Photoconductivity in a-SeTe

In-quadrature frequency-resolved photocurrent (FRPC) measurements were performed on amorphous SeTe films between 20 K and 290 K, and as a function of excitation intensity. These measurements yield lifetime distributions directly. The results show that the recombination takes place between distant pairs and that there is a continuous distribution of states within the mobility gap.

Photocurrent Measurements in Operating a‐Si:H p‐i‐n Solar Cells with Different P‐Layer Conditions

I‐V characteristics, light intensity‐ and modulation frequency‐ dependences, and spectral distributions of photocurrent of three‐types of a‐Si:H p‐i‐n devices with different p‐layer conditions (baseline, thinner and thicker) have been measured at room temperature. Dc and chopped light from a HeNe laser were used for excitation. From the results, the fill‐factor, quantum efficiency, carrier lifetime, and the exponent v in the power‐low relationship, Iph ∼ Gv between photocurrent and generation rate were obtained and compared under different bias conditions and modulation frequencies. The results were interpreted suitably due to radiation loss and recombination mechanisms.

Frequency-resolved photoconductivity studies in amorphous As2Se3

Abstract Frequency-dependent photocurrent measurements were carried out on amorphous As2Se3 thin films between 20 and 290 K, by using the quadrature frequency-resolved spectroscopy method which yields lifetime distributions directly. The results show that the lifetime depends on excitation light intensity and temperature and thus they give information about recombination kinetics.