CIGSS thin film solar cells: final subcontract report, 11 October 2001-- 30 June 2005

Original publisher: Golden, Colo. : National Renewable Energy Laboratory, [2006] OCLC Number: (OCoLC)216928985 Subject: Photovoltaic cells -- Research. Excerpt: ... no intermediate dwell. The sample showed patches of dark and light gray area as seen in Figure 10a. Sheet resistance in the dark areas was 1.4 kΩ / □ and 1 kΩ / □ in the light gray areas. Overall the film was slightly copper-rich which was evident from the CuSe whiskers seen in the SEM micrograph ( figure 10 b ). Experiment # 10-To study the effect of reduced ramp rate o In another experiment, the ramp rate was reduced to 6 C / minute. This sample showed a patch too as seen in Figure 10c. However, the film showed overall uniformity compared to the film shown in Figure 10a. The sheet resistance was 300 to 500 Ω / □ and the thickness was 3.8 to 3.9 µm. SEM image is shown in Figure 10d. Figure 10c: Se / S treated sample 10b Figure 10d: SEM of sample 10b The grain size varied from < 1 µm to 2 µm in all the samples. Sulfur quantity was higher in all the films. Cells were completed and efficiency was measured. The values obtained were not very attractive and it was inferred that the process needs to be modified to optimize the parameters to obtain good quality absorber. Heterojunction Partner Layer, CBD CdS Heterojunction partner CdS layers were satisfactorily deposited by chemical bath 2 deposition on 10 x 10 cm CIGS2 samples. The CdS deposition set-up was modified to reduce the quantity as well as to ensure uniform heating of the solution. A 4000 ml beaker was used as a water bath while the reaction solution was prepared in a 1000 ml 10