Buffer layers and transparent conducting oxides for chalcopyrite Cu(In,Ga)(S,Se)₂ based thin film photovoltaics: present status and current developments

Abstract

The aim of the present contribution is to give a review on the recent work concerning Cd-free buffer and window layers in chalcopyrite solar cells using various deposition techniques as well as on their adaptation to chalcopyrite-type absorbers such as Cu(In,Ga)Se 2 , CuInS 2 , or Cu(In,Ga)(S,Se) 2 . The corresponding solar-cell performances, the expected technological problems, and current attempts for their commercialization will be discussed. The most important deposition techniques developed in this paper are chemical bath deposition, atomic layer deposition, ILGAR deposition, evaporation, and spray deposition. These deposition methods were employed essentially for buffers based on the following three materials: In 2 S 3 , ZnS, Zn 1 À x Mg x O.

Sulfurization-induced growth of single-crystalline high-mobility β-In2S3 films on InP

“…The constituent phases and structure of In 2 S 3 films were probed by Raman spectroscopy, with the positions of the observed prominent peaks (137.6, 163.3, 181.9, 246.9, 267.6, 304.4, 341.12, and 366.23 cm -1 (Fig. 4a)) being in close agreement with those previously obtained for tetragonal β-In 2 S 3 films (137, 164, 182, 247, 268, 309, 328, and 369 cm -1 ), 2,18,19 confirming that the prepared films comprised tetragonal β-In 2 S 3 . Prior studies reported that the direct and indirect bandgaps of β-In 2 S 3 films varied within the ranges of 1.9-2.75 and 1.98-2.2 eV, respectively.…”

“…© 2017 Author (s The environmentally friendly nature of group IIIA metal chalcogenides together with their suitable bandgaps and superior optical properties/photoconductivities make them promising materials for a range of optoelectronic and photocatalytic applications. [1][2][3][4][5][6][7] In particular, In 2 S 3 is used in the buffer layers of copper indium gallium diselenide solar cells and in the absorber layers of intermediateband solar cells. 2,8 However, the above sulfide undergoes a number of thermally induced phase transitions to afford α (cubic), β (tetragonal), and γ (hexagonal) phases 9 with tetragonal β-In 2 S 3 being the most thermodynamically stable (and thus, the most studied) phase at room temperature.…”

“…[1][2][3][4][5][6][7] In particular, In 2 S 3 is used in the buffer layers of copper indium gallium diselenide solar cells and in the absorber layers of intermediateband solar cells. 2,8 However, the above sulfide undergoes a number of thermally induced phase transitions to afford α (cubic), β (tetragonal), and γ (hexagonal) phases 9 with tetragonal β-In 2 S 3 being the most thermodynamically stable (and thus, the most studied) phase at room temperature. Importantly, tetragonal β-In 2 S 3 thin films exhibit a wide range of bandgaps (1.64-3.7 eV) 10,11 e.g., a direct bandgap of 1.9 ± 0.3 eV was recently determined by photoluminescence (PL) and photoconductivity measurements.…”

Fabrication of solar cells based on Cu2ZnSnS4prepared from Cu2SnS3synthesized using a novel chemical procedure

“…in the solution), or heterogeneous phase (i.e. in the substrate) [15,16], and the thin film formation takes place when the ionic product exceeds the solubility product.…”

Zn(O, S) layers for chalcoyprite solar cells sputtered from a single target

“…Zn(O, S) is emerging as one of the most promising materials to replace CdS in the buffer layer of chalcopyritebased thin-film solar cells [1]. Successful preparation technologies include chemical bath deposition and atomic layer deposition.…”