CIGS absorber preparation by non-vacuum particle-based screen printing and RTA densification

摘要

CuIn0.7Ga0.3Se2 (CIGS) thin-films are prepared by the particle-based screen printing technique followed by rapid thermal annealing (RTA) densification. Due to the short RTA time, CIGS absorber remains the ideal stoichiometric ratio originated from the CIGS particles in the coating paste and thus the conventional selenization process is not required. The effects of the particle concentrations of the coating paste, the RTA temperature and normal loading during RTA on the performances of the CIGS thin-films are studied. The film thickness increases with the increase of the particle concentration of the coating paste. The carbon content of the film is nearly zero when the RTA temperature is greater than 650 degrees C. The carrier concentration and Hall mobility of the CIGS film increase when increasing the RTA temperature from 300 degrees C to 650 degrees C. Using the coating paste with a particle concentration of 40 wt% for screen printing and a three-step, 250 degrees C solvent removal for 5 min, 500 degrees C annealing for 7 min and 650 degrees C densification for 3 min, 1.97 N cm(-2) normal loading RTA process, a p-type chalcopyrite CIGS film with the carrier concentration of 1.23 x 10(15) cm(3) and mobility of 26.21 cm(2) V-1 s(-1) is obtained. (C) 2015 Elsevier Ltd. All rights reserved.