Short communication Prediction of photovoltaic p–n device short circuit current by photoelectrochemical analysis of p-type CIGSe films Diego Colombara a, ⁎, Alexandre Crossay a , David Regesch a , Cedric Broussillou b , Thomas Goislard de Monsabert b , Pierre-Philippe Grand b , Phillip J. Dale a a Physics and Materials Research Unit, Université du Luxembourg, 41, rue du Brill, L-4422 Belvaux, Luxembourg b Nexcis, 190 av. Célestin Coq, Zone Industrielle, 13790 Rousset, France abstract article info Article history: Received 14 August 2014 Received in revised form 27 August 2014 Accepted 27 August 2014 Available online 4 September 2014 Keywords: Photocurrent spectroscopy Cu(In,Ga)Se 2 Opto-electronic quality Photoluminescence Short-circuit-current The quality control of individual semiconductor thin films during fabrication of multiple layers is important for industry and academia. The ultimate aim of this research is to predict the efficiency of p–n junction solar cells by photoelectrochemical analysis of the bare p-type semiconductor. A linear correlation between the photocurrent measured electrochemically on Cu(In,Ga)Se 2 absorber layers through a Eu 3+ electrolyte junction and short circuit current and efficiency of the corresponding solid state devices is found. However, the correlation is complicated by pronounced recombination at the semiconductor/electrolyte interface, while the solid state interface behaves more ideally. © 2014 Elsevier B.V. All rights reserved. 1. Introduction Being able to predict the final efficiency or photovoltaic (PV) proper- ties of a p–n junction solar cell from analysis of just the p-type semicon- ductor film before the addition of the four subsequent layers required to complete the device would allow a cost effective control of the produc- tion line (Fig. 1). Besides suggesting if device completion is worthwhile, accurately assessing PV potential would also provide academic groups without device completion facilities the means of estimating potential conversion efficiencies. Hence, the goal of this research is to develop a photoelectrochemical (PEC) method to test the PV potential of p-type semiconductor thin films on conductive substrates. The underlying assumption of this work is that overall device efficiency is dominated by the quality of the p-type semiconductor layer. The hypothesis is that a measurable PEC parameter can be corre- lated to the PV device efficiency. Device efficiency is proportional to the product of the short circuit current density (J SC ) and the open circuit voltage. J SC is proportional to the collection length of excited charge carriers, and if single-junction devices with same band-gap semicon- ductors are considered [1], it is a reasonable predictor of efficiency (Fig. 1). If a PEC parameter could be correlated to J SC , a relationship with the final device efficiency would be established. In a very close similarity with p–n junctions, the electrical behavior of p-semiconductor/electrolyte junctions as a function of the applied bias can be expressed by the diode equation [2], and is shown schemat- ically in Fig. 1. The theory of semiconductor electrochemistry has been extensively reviewed by Memming, to whom the reader is referred [3]. This similarity with the p–n junction made possible the design of a number of PEC solar cells [12–15] that in the case of n-type semiconduc- tors have achieved power conversion efficiencies as high as 15% [16]. Issues of semiconductor photocorrosion, as well as surface instability under prolonged operation have somehow discouraged their further development. Nevertheless, optically transparent semiconductor/ electrolyte junctions, with their near-reversibility and fast implementa- tion, have been viably and widely employed [17] to characterize single [18–20] and polycrystalline [21–33] semiconductor materials. Informa- tion such as conductivity type [29,30], band-gap and flat-band potential [31], doping density [25,33], as well as insights on the presence of opti- cally absorbing phases on the film surface [32] have been obtained. This versatility is appealing for the development of a method aimed at screening PV semiconductor properties. Perhaps due to its relation- ship with J SC and to the simplicity of the measurement, photocurrent density (J Ph ) remains the most reported PEC parameter. However, it is known that the theoretical correlations between solid state and PEC solar cells are complicated by experimental issues including the non- ideality of surface structures and current collection at the semiconduc- tor/electrolyte interface [34]. In this sense, the present work aims at explicitly testing if the corre- lation between J SC and J Ph holds satisfactorily, and thus if J Ph can be con- sidered a suitable indicator for the quality assessment of thin films for PV applications. This is an important research question that has never Electrochemistry Communications 48 (2014) 99–102 ⁎ Corresponding author. E-mail address: diego.colombara@uni.lu (D. Colombara). http://dx.doi.org/10.1016/j.elecom.2014.08.026 1388-2481/© 2014 Elsevier B.V. All rights reserved. Contents lists available at ScienceDirect Electrochemistry Communications journal homepage: www.elsevier.com/locate/elecom