Deep Level Studies in High-Resistive Gallium Phosphide Single Crystals

作者：Das Sandip; Chaudhuri Sandeep K; Mandal Krishna C^*

来源：ECS Journal of Solid State Science and Technology, 2016, 5(4): P3059-P3063.

DOI：10.1149/2.0101604jss

In an attempt to explore the possibility of using wide bandgap gallium phosphide (GaP) single crystals as radiation detectors, high resistivity iron (Fe)-doped GaP single crystal was grown using a solid state diffusion (SSD) technique. The grown ingot showed a resistivity in the order of 10(8) Omega-cm with an optical bandgap of 2.27 eV measured at room temperature. Schottky barrier diodes were fabricated by sputtering nickel (Ni) contacts on GaP wafers to study the deep level defects and junction properties. An effective donor concentration, N-d = 2.6 x 10(16) cm(-3) was calculated from the capacitance-voltage measurements. Deep level transient spectroscopy (DLTS) and current transient spectroscopy (CTS) were performed on the Schottky diodes to identify the electrically active defect levels in the grown high-resistive GaP crystals. DLTS measurements revealed the presence of several vacancies, impurities, and antisite defects centers with concentrations ranging from 10(14) - 10(16) cm(-3). CTS measurements identified a new defect level in GaP crystals that could not be detected by the conventional DLTS scan due to very fast capacitance transients at temperatures below 100 K.

• 出版日期2016