Preparation and investigation of (CuInSe₂)_x(2ZnSe)_1‐x and (CuInTe₂)_x(2ZnTe)_1‐x solid solution crystals

Abstract

Preparation and investigation of (CuInSe 2 ) x (2ZnSe) 1-x and (CuInTe 2 ) x (2ZnTe) 1-x solid solution crystals The (CuInSe 2 ) x (2ZnSe) 1-x and (CuInTe 2 ) x (2ZnTe) 1-x solid solution crystals prepared by Bridgman method and chemical vapor transport have been studied. The nature of the crystalline phases, the local structure homogeneity and composition of these materials have been investigated by X-ray diffraction (XRD) and Electron Probe Microanalysis (EPMA) methods. The analysis revealed the presence of chalcopyrite-sphalerite phase transition between 0.6 ≤ X ≤ 0.7. Lattice constants, value of σ position parameter and bond length between atoms were also calculated. It was found that the lattice parameters exhibit a linear dependence versus composition. The transmission spectra of solid solution crystals in the region of the main absorption edge were studied. It was established that the optical band gap of these materials changes non-linearly with the X composition.

Investigation of CuInZnSe2 thin films for solar cell applications

“…The data obtained for the optical energy gaps of CIZSe thin films are summarized in Table 1. Similar results have been reported for bulk materials [9,10]. The band gap energy varies nonlinearly with the composition of (CuInSe 2 ) 1ÀX (2ZnSe) X thin films.…”

“…The band gap energy varies nonlinearly with the composition of (CuInSe 2 ) 1ÀX (2ZnSe) X thin films. This phenomena has been already observed in the crystals of solid solutions formed by the A II B VI -A I B III C 2 VI compounds [6,8,10]. The large difference between E g of the binary compound ZnSe and CuInSe 2 is explained as the band gap anomaly of the ternary compounds.…”

“…They are isoelectronic analogs of the A II B VI binary compounds and crystallize in the chalcopyrite structure, which is closely related to that of zincblende [2]. Interest in studying systems A I B III C 2 VI -A II B VI has grown considerably since the fabrication of heterostructures for solar cells [4][5][6][7][8][9][10]. Compared to pure CuInSe 2 the (CuInSe 2 ) 1ÀX (2ZnSe) X (CIZSe) solid solutions give the advantage of band gap E g tunability from E g =1.04 eV (CuInSe 2 ) to E g =2.67 eV (ZnSe).…”

Evolution of nanostructure, phase transition and band gap tailoring in oxidized Cu thin films

“…Formation of mixed crystalline CdS and ZnS semiconductors upon controlled vacuum deposition has been inferred from the observed linear relationship between band gap energy and composition of phases [49]. But Bodman et al [50] reported a non-linear dependence of energy gap with composition of phases in (CuInSe 2 ) x (2ZnSe) 1 − x and (CuInTe 2 ) x (2ZnTe) 1 − x solid solutions. In the present study, the film samples are composed of a direct band gap semiconductor (Cu 2 O) and an indirect band gap semiconductor (CuO), and we observed a linear variation of the band gap with temperature of oxidation.…”

Band gap engineering of RF-sputtered CuInZnSe2 thin films for indium-reduced thin-film solar cell application

“…In conjunction with the effort of reducing indium in thin-film solar cells, recently, the novel (CuInSe 2 ) 1Àx À(2ZnSe) x alloy for solar cell application has attracted a considerable attention since the first successful fabrication of CuInZnSe 2 (CIZSe) thin-film solar cell [3]. The (CuInSe 2 ) x À(2ZnSe) 1Àx solid solution was reported to have a band gap variation from 1.0 eV (CuInSe 2 ) to 2.67 eV (ZnSe) and a high absorption coefficient (10 4 cm À1 ) within the visible and nearinfra-red regions [3,4]. The motivation underlying this effort was to follow by analogy the band gap engineering of a chalcopyrite CuInSe 2 when it is alloyed with CuGaSe 2 .…”