Surface treatment of CuInGaSe2 thin films and its effect on the photovoltaic properties of solar cells

Extrinsic doping effect in the fabrication of CIGS and CIGSS thin film solar cells

“…These differences are attributed, at least partly, to a higher recombination current in the Cd PE junction. We have found this effect to be true for CIGS thin films grown in our laboratory and CIGSS samples grown by an entirely different process in a manufacturing environment [4]. The results lend credence to the hypothesis that the presence of Cd in the CBD environment is creating a powerful electronic effect at the surface region of the absorbers.…”

“…They exhibited very poor junction characteristics. The experimental procedures have been adequately described in a previous paper [4]. Current-voltage (I-V) characteristics were measured by illuminating the solar cells with AM1.5 Global spectrum of 1000 W/m 2 irradiance.…”

Intermixing and Formation of Cu-Rich Secondary Phases at Sputtered CdS/CuInGaSe2Heterojunctions

“…Abou-Ras et al [8] suggested that the absence of a Cd doping layer on the CIGS surface in PVD-CdS/CIGS heterojunctions, and thus the lack of a p-n homojunction, may explain the efficiency deficit. Indeed, Ramanathan et al [9,10] showed that Cd insertion into the CIGS surface may hold the key to the success of CBD-CdS/CIGS solar cells by comparing the efficiencies of a series of CIGS solar cell devices in which the CIGS surfaces were treated in different CBD solutions. Although the Cd-doped CIGS surface in CBD-CdS/CIGS junction has been experimentally verified [11,12], no direct evidence of Cd doping on the CIGS surface in PVD-CdS/CIGS is available.…”

The CuInSe2–CuGaSe2–2CdSe system and crystal growth of the γ-solid solutions

“…These compounds are readily obtained with the p-type conductivity and, in combination with the n-type CdS, can form the p-n heterojunction necessary for the separation of photo-generated carriers. A remarkable property of chalcopyrites is their ability to form solid solutions, CuInS x Se 2−x [4,5], CuIn x Ga 1−x Se 2 [1,2,6], CuIn x Ga 1−x S y Se 2−y [1,7,8], etc., which not only allow tuning the semiconductor band gap to achieve the maximum photoconversion efficiency but also ensure the observed high tolerance to compositional variations. In this respect, the investigation of phase relations between ternary chalcopyrites together with other II-VI compounds is important to assess possible element interdiffusion at the p-n heterojunction and to extend the knowledge about solid solutions and possible intermediate phases.…”