Optical investigations on sputtered CuCl thin films

Abstract

ABSTRACTCopper (I) chloride (CuCl) is a potential candidate for ultra violet optoelectronics due to the fact that it is closely lattice matched with silicon, which makes it readily integrable with silicon device technology. The structural and optoelectronic properties of CuCl thin films deposited by RF magnetron sputtering are investigated. The crystallinity is studied using X-ray diffraction which confirms the growth of CuCl thin films with cubic zinc blende structure predominantly orientated in <111> direction. Excitonic transitions in the thin films were thoroughly investigated using optical absorbance and luminescence spectroscopies. Room temperature absorption spectroscopic analysis confirms the existence of two exciton peaks namely Z12 and Z3 at 372 and 380 nm respectively. A strong UV emission is observed at room temperature in cathodoluminescence and photoluminescence spectra due to the recombination of Z3 exciton at approximately 384 nm. In the low temperature photoluminescence spectrum, a free exciton (Z3) and a bound exciton (I1) are observed. A variation of 1.3 nm to 10 nm was observed in the Z3 exciton line width from 10 K to 300 K.