Impact of CdTe surface composition on doping and device performance in close Space sublimation deposited CdTe solar cells. (2nd November 2011)

• Record Type: Journal Article
• Authors: Major, J. D.; Proskuryakov, Y. Y.; Durose, K.
• Is Part Of: Progress in photovoltaics. Volume 21:Number 4(2013)
• Page Start: 436
• Page End: 443
• Publication Date: 2011-11-02
• Subjects: Solar cells -- Periodicals; Photovoltaic cells -- Periodicals; Solar power plants -- Periodicals; 621.31245
• DOI: 10.1002/pip.1196
• Languages: English
• ISSNs: 1062-7995

Abstract

<abstract abstract-type="main"> <title>ABSTRACT</title> <p>Cool‐down after close‐space sublimation growth of cadmium telluride films has been shown to lead to the formation of a Cd‐rich surface that can block the subsequent in‐diffusion of cadmium chloride that is used in post‐growth doping of solar cell devices. Pre‐etching of the as‐grown surfaces using a nitric–phosphoric acid etch prior to doping leads to increase in chlorine and oxygen in‐diffusion, and an associated improvement in device efficiency from &lt;3% to 12% in controlled trials. Capacitance‐voltage analysis of such devices revealed an increase in the acceptor concentration from 3.76 × 10¹³ cm⁻³ to 5.6 × 10¹⁴ cm⁻³, whereas thermal admittance spectroscopy revealed fewer deep states at energies &gt;0.4 eV for etched devices. Impedance analysis showed the improved cadmium chloride treatment—resulting from the additional etching step—removed the grain boundary component from the equivalent circuit, indicating a grain boundary passivation effect. Copyright © 2011 John Wiley &amp; Sons, Ltd.</p> </abstract>