Patent ID: 6660538
Filing Date: 2003-12-09
Classification: C23C,H01L,Y02E

Abstract:
A method for depositing a chalcopyrite structured semiconductor thin film onto a substrate from at least a first source and a second source, and controlling the thin film's achievable solar conversion efficiency; comprising:a) controlling the first source-to produce a first particle flux incident on the substrate and controlling the second source to produce a second particle flux incident on the substrate, thereby producing a first deposited thin film; b) monitoring the first deposited thin film's achievable solar conversion efficiency by: i) irradiating at least a portion of said first deposited thin film's surface with light comprising a plurality of wavelengths; ii) detecting light reflected from said first deposited thin film's surface with a spectrophotometric device that produces an output signal directly related to the color of said first deposited thin film's surface; and iii) comparing the output signal with a predetermined measure of the achievable solar conversion efficiency of said first deposited thin film and producing a control signal thereby; c) feeding said control signal back so as to control at least one of the first source and the second source in order to produce a second deposited thin film of better achievable solar conversion efficiency than the said first deposited thin film.