Quality CuInSe₂and Cu(In,Ga)Se₂thin films processed by single-step electrochemical deposition techniques

Vacuum and Liquid-Phase Processing of ZnSe Buffer-Layer for Chalcopyrite Absorber Based Photovoltaic Technology

“…In case of ZnSe deposited by CBD on polycrystalline quaternary selenides Cu(In,Ga)Se 2 (Fig. 22 and 23), however, the usually observed ZnSe Bragg reflection peaks overlap with the peaks of the chalcopyrite selenide and its secondary copper diselenide phases 122,123,142,145 as demonstrated in Fig. 22a.…”

“…Absorbers not undergoing this Cu-surplus stage are generally semi-insulating, which is assumed to be due to a high concentration of sulfur or selenium vacancies acting as compensating donors. 12 In case of chalcopyrite selenides, associated with the Cu-excess secondary microcrystalline Cu x Se phases on chalcopyrite absorber surface, [92][93][94]141,142 increase the inhomogeneous tensile strain that the absorber exhibits as result of the lattice mismatch to the underlying Mo/glass substrate and additionally red-shift, 94,143 the chalcopyrite three valence-split bands: E a , E b , E c 1 canceling partially the band-gap up-shift pursued by Ga addition to ternary CuInSe 2 to form the quaternary Cu(In,Ga)Se 2 alloy. 144 Prior to ZnSe deposition by CBD, wet chemical etching of the chalcopyrite surface with potassium cyanide (KCN) is thus mandatory in order to remove oxides and Cu x Se crystallites.…”

Engineering of Optical and Electrical Properties of Electrodeposited Highly Doped Al:ZnO and In:ZnO for Cost-Effective Photovoltaic Device Technology

“…The field of ZnO research and applications has widely been scanned, in the past and at present, as already reported in our recent publications [1][2][3][4]. Our efforts are primarily focused on the engineering of the structural, optical, and electrical properties of chalcopyrite semiconductor based thin-film solar cells (TFSCs) [5][6][7][8][9][10][11][12][13] with Cu(In,Ga)Se 2 (CIGS) absorber [1], ZnSe buffer [4], and ZnO window, front-contact, and antireflective coating (ARC) [2,3] processed by electrochemical deposition (ECD) techniques. Electrodeposition with cost-effective, large-area, moderate-temperature, fast-rate performance can be scaledup to industrial processes.…”

“…Electrodeposition with cost-effective, large-area, moderate-temperature, fast-rate performance can be scaledup to industrial processes. Overall processing of CIGS chalcopyrite selenide absorber [1], ZnSe buffer with alternate cubic/sphalerite and hexagonal/wurtzite structure to relax (elastic) strain/stress [4] in the layer sequence, ZnO window of highly to ultra-highly doped ZnO bilayer [3] to effectively accelerate and collect carriers, and ZnO-Nanorod (ZnO-NR) ARC [2] by ECD is targeted to overcome current process incompatibilities. Common disadvantages of flow-oriented production of commercialized CuInS 2 (CIS) and CIGS TFSCs result mainly from the simultaneous use of moderate temperature (50-70 • C) non-vacuum and high-temperature (500-700 • C) vacuum processes applied to the absorber (multi-step evaporation at elevated temperatures [14,15]), buffer (chemical bath deposition at moderate temperatures [16][17][18][19][20]), and window (sputtering at high temperatures [21][22][23][24][25][26]) layers.…”

Effect of In-Incorporation and Annealing on CuxSe Thin Films

“…CuInSe 2 films can be formed using various deposition methods. Chemical deposition methods include spin-coating [ 6 ], electrochemical deposition [ 7 ], and chemical bath deposition [ 8 ], while physical deposition methods include electron beam evaporation [ 9 ], sputtering [ 10 ], molecular beam epitaxy [ 11 ], physical vapor deposition [ 12 ], printing [ 13 ], etc. Films which are formed using physical deposition methods are usually more uniform and of better quality; however, expensive, high-temperature, and low-pressure equipment is often needed.…”