High rate (~7 nm/s), atmospheric pressure deposition of ZnO front electrode for Cu(In,Ga)Se 2 thin-film solar cells with efficiency beyond 15

• Published in: Progress in photovoltaics Vol. 21; no. 8; pp. 1559 - 1566
• Main Authors: ILLIBERI, Andrea, GROB, Frank, FRIJTERS, Corne, POODT, Paul, RAMACHANDRA, Ram, WINANDS, Hans, SIMOR, Marcel, JAN BOLT, Pieter
• Format: Journal Article
• Language: English
• Published: Bognor Regis Wiley 01-12-2013
• Subjects: Applied sciences; Energy; Exact sciences and technology; Natural energy; Photovoltaic conversion; Solar cells. Photoelectrochemical cells; Solar energy; Performance evaluation; Conducting material; Electrical conductivity; Indium selenides; Scalability; Atmospheric pressure; Glass; Coatings; transparent conductive oxides; Thin film; Near ultraviolet radiation; plasma-enhanced chemical vapor deposition; Thin film cell; Zinc oxide; Visible spectrum; PECVD; Copper; Low temperature; Atomic layer method; Deposition rate; Coated material; thin films; Solar cell; Thickness; Copper selenides; Ultraviolet radiation; Quaternary compound; solar cells; Alumina; Transparent material; Gallium selenides; Room temperature
• ISSN: 1062-7995; 1099-159X
• DOI: 10.1002/pip.2423

Undoped zinc oxide (ZnO) films have been grown on a moving glass substrate by plasma‐enhanced chemical vapor deposition at atmospheric pressure. High deposition rates of ~7 nm/s are achieved at low temperature (200 °C) for a substrate speed from 20 to 60 mm/min. ZnO films are highly transparent in the visible range (90%). By a short (~minute) post‐deposition exposure to near‐ultraviolet light, a very low resistivity value of 1.6·10
−3
 Ω  cm for undoped ZnO is achieved, which is independent on the film thickness in the range from 180 to 1200 nm. The photo‐enhanced conductivity is stable in time at room temperature when ZnO is coated by an Al
2
O
3
barrier film, deposited by the industrially scalable spatial atomic layer deposition technique. ZnO and Al
2
O
3
films have been used as front electrode and barrier, respectively, in Cu(In,Ga)Se2 (CIGS) solar cells. An average efficiency of 15.4 ± 0.2% (15 cells) is obtained that is similar to the efficiency of CIGS reference cells in which sputtered ZnO:Al is used as electrode. Copyright © 2013 John Wiley & Sons, Ltd.