New processing developments in the Cu(In,Ga)Se 2 (CIGS)-based solar cell technology have enabled progress to the next level of best cell efficiencies exceeding 21%. This result was achieved by ...applying the alkali post-deposition treatment (PDT) to the CIGS film, which effects changes both in the bulk and on the surface of the film. Furthermore, we have found that these modifications affect the range of optimal CIGS growth parameters and the minimal thickness of the CdS buffer layer. Our first experiences with PDT lead to a 20.8% record device. Later optimizations in the composition profile and CdS buffer layer thickness enabled us to increase the photocurrent density with only a slight loss in open-circuit voltage and unchanged fill factor, resulting in the current world record of 21.7% efficiency. This contribution presents measurements, simulations, and a discussion of the photocurrent increase.
Thin-film solar cells that are based on Cu(In,Ga)Se 2 (CIGS) absorbers with Ga/(Ga+In)-ratios from 0 to 1 are fabricated, and their optical and electrical properties are investigated by macroscopic ...(current density-voltage, external quantum efficiency) and microscopic (Kelvin probe force microscopy on untreated cross sections of solar cells) measurements. Combining all results, the diffusion voltages of individual solar cells are deduced and compared with the directly measured open-circuit voltages. An increasing splitoff between the diffusion voltage and the opencircuit voltage is observed forGa addition,which indicates a higher recombination rate of photogenerated charge carriers in solar cells with higher Ga content.
Polycrystalline silicon for thin film solar cells Bergmann, R.; Kuhnle, J.; Werner, J.H. ...
Proceedings of 1994 IEEE 1st World Conference on Photovoltaic Energy Conversion - WCPEC (A Joint Conference of PVSC, PVSEC and PSEC),
1994, Volume:
2
Conference Proceeding
The authors report on the characterisation of epitaxial Si on Si substrates grown at temperatures around 450/spl deg/C as one prerequisite for crystalline Si deposition on low temperature resistant ...foreign substrates and describe two novel approaches aimed to produce large grained seeding films for subsequent polycrystalline Si deposition on glass substrates. A modified solution growth process at temperatures around 600-650/spl deg/C produces polycrystalline Si seeding films with grains laterally extending several 100 /spl mu/m on borosilicate glass substrates. In it second approach, the authors use polycrystalline /spl beta/-FeSi/sub 2/ films as a seed for Si deposition.
