Synthesis and physical properties of solar material Cu_1+xIn_1‐xSe₂

Abstract

Bulk samples of Cu1+xIn1‐xSe2 (x = 0–0.5) have been prepared by solid‐state reaction method at 1073 K. The crystal structure, thermal stability, optical absorbance and electrical properties were systematically studied. With the value x increasing from 0 to 0.5, the optical band gap is gradually reduced from 0.90 to 0.86 eV, moreover, the room temperature electrical conductivity has been greatly enhanced from 5 to 850 S/cm, but the Seebeck coefficient is slightly decreased from 80 to 57 µV/K even at 625 K. It is likely that lattice distortions, additional holes, and/or second phase introduced by Cu doping lead to these changes.

Shape-dependent optoelectrical investigation of Cu2+xCd1−xSnS4thin films for solar cell applications

“…A similar trend was reported for Cu-doped Cu 2 CdSnS 4 films by Min-Ling Liu et al 41 However, the E g values of the present results are relatively low, which is attributed to the valence band maximum (VBM) caused by the stronger hybridization of Cu 3d and S 4p orbitals with the increasing Cu-doping concentration. 42 The high absorption coefficient (in the range of 400-600 nm) and the tunable band gap of Cu 2+x Cd 1Àx SnS 4 thin films would be advantageous for absorber layers of solar energy devices and photovoltaic applications. The variation in bandgap energy of Cu 2+x Cd 1Àx SnS 4 thin films proposes that the optical properties of the thin films can be controlled by varying the Cu doping concentration.…”