Optoelectronic characterization of chemically synthesized CuxIn1-xSe2 nanostructure for suitable application as photoconductive device

CuxIn1-xSe2 nanostructures have been synthesized chemically using Polyvinyl Pyrrolidone (PVP) as capping agent by varying the Cu/In composition ratio. XRD results confirm the formation of cubic CuSe2 and that of wurtzite phase of CuxIn1-xSe2 nanostructure. SEM and TEM images showed spherical shaped particle distribution of CuSe2 and hexagonal sheet/plate shaped CuxIn1-xSe2 nanostructures which are in well agreement with XRD pattern. EDAX spectra for both the structures confirm the presence of Cu, In & Se atomic(%) along with some impurity atoms. Optical band gaps calculated from Tauc plots are found to decrease from 2.5 eV to 1.4 eV from CuSe2 to In-rich CuxIn1-xSe2 samples. The conductivity of the samples shows a significant increase of current with the increase of Indium composition which are co-related with the optical band gap of the samples. A comparative analysis has also been done on Schottky and hetero structure of the CuxIn1-xSe2 samples for suitable application in photovoltaic device. The performance of CuxIn1-xSe2 nanostructures has been analyzed through photoresponse studies under illumination of 546 nm monochromatic light for their fruitful application in photoconductive devices. The efficiency of devices is found to increase with % of Indium.