The electrical characterizations and illumination response of Co/N-type GaP junction device

Abstract

The manuscript describes characterization of a Co/n-GaP junction device. The current–voltage–temperature (I–V–T), capacitance–frequency–temperature (C–f–T) measurements of the device were analyzed in the temperature range of 60–320 K by the steps of 20 K under dark condition, and light condition at room temperature. The characteristic parameters such as barrier height (BH), ideality factor (n) have been determined from the forward bias I–V characteristics on the basis of standard thermionic emission. The BH and n were found to be 0.98 eV and 1.05 at room temperature, respectively. The ideality factor increased and BH decreased with a decrease in temperature. The BH and n were found to be linear dependent on each other at two different regions, and these values are predicted with existence of Gaussian distribution (GD). For the two different methods the BH is seen in good agreement with each other. Especially, the homogeneous BH for the first region is found to around 1.02 eV. The homogeneous BH values are found to be good agreement for 3 different methods such as the linear correlations of BH versus n plot, GD of BHs and Norde's function. Interface states (Nss) and their time constant (τ) were calculated from the C–f–T measurements and as sample temperature was increased, the Nss value increased and τ decreased in dark conditions. Photovoltaic parameters such as fill factor (FF), power conversion efficiency (ηp), open circuit voltage (Voc) and short circuit current (Isc) were calculated. According to these, it was been seen that the semiconductor device under light illumination showed photovoltaic behavior.