Optoelectronics characteristics of chemically synthesized Cu(In1-xGax)Se2 based Schottky and heterojunctions

• Published in: Optical materials 2023-11, Vol.145, p.114420, Article 114420
• Main Authors: Barman, Barnali, Handique, K.C., Kalita, P.K.
• Format: Article
• Language: English
• Subjects: CIGSe2; Hetero-junction diode; Nonlinear I-V; Optical band gap
• ISSN: 0925-3467; 1873-1252
• DOI: 10.1016/j.optmat.2023.114420

CIGS is an important photovoltaic material in recent years. In this work, we have performed a comparative analysis of various conduction mechanism in CIGSe2 based Schottky and hetero junction nanostructures. Cu(In1-xGax)Se2 nanostructure dispersed in PVP matrix has been synthesized through chemical bath deposition method at a compositional variation x = 0-1. The structural and optical characterization are done and correlated with the In/Ga fraction ratio. The conduction mechanism for both Schottky and hetero structures has been analyses and systematically co-related with compositional variation of In/Ga. By using the thermionic theory, the diode parameters ideality factor, saturation current, barrier height is determined in hetero junction device and co related with composition of Cu(In1-xGax)Se2. Richardson-Schottky(RS) mechanism is found to be dominant in Schottky type junction whereas both Pool-Frenkel(PF) and Richardson-Schottky(RS) mechanism is involved in hetero junction at different range of bias. Our findings points to Cu(In1-xGax)Se2 nanostructures synthesized at x = 0, 0.3,0.5 as promising candidate for solar cell because of their optimum diode parameters and band gap for absorption of maximum solar radiation. •PVP capped Cu(In1-xGax)Se2 have been synthesized chemically at x=0-1.•CIGSe2 shows tetragonal chalcopyrite structure.•The optical band gap has increased from 1.3eV to 2eV suitable for solar cell.•Both Pool-Frenkel and Richardson-Schottkyeffect is involved in conduction.•The barrier height and saturation current is a function of In/Ga.