Tham khảo tài liệu 'solar cells thin film technologies part 10', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Innovative Elastic Thin-Film Solar Cell Structures 259 Fig. 6. SEM picture and the diagram of CdS wurtzite grains with vertical growth orientation and CdS hexagonal grain model. to achieving of this structure under some technology circumstances 17 and may be matched with crystal constant differences not higher than 9 7 18 . Structure of model CdS layer obtained by authors organized in wurtzite phase is presented in Figure 6. The most popular manufacturing technologies of CdS CdTe solar cells are nowadays CVD Chemical Vapour Deposition and the variants like PECVD ang Plasma Enhanced CVD or MOCVD Metall Organic Chemical Vapour Deposition 19 CBD Chemical Bath Deposition and physical methods like PVD Physical Vapour Deposition CSS Close Space Sublimation 20 and variants of CSVT Close Space Vapour Transport 21 22 . Alternatively screen-printing technology was also successfully employed for production of relatively thick CdTe base 23 . Morphology of the last mentioned layers was verified by authors with the help of SEM analysis indicating dense compact structure of hexagonal grains Figure 7 . Fig. 7. SEM picture of dense compact CdTe grain layer up to 8 pm manufactured by ICSVT technology on glass substrate. As the additional experiments AFM profile of this layer presented in Figure 8 was prepared. 260 Solar Cells - Thin-Film Technologies Fig. 8. AFM profiling of CdTe polycrystalline layer made by ICSVT technology. This measurement gives some important information about grains structure and intercrystal surfaces. By means of polycrystalline CdS CdTe layers profiling one may easily detect the diameter and grain shape but also the inter-grain valleys depth and possible structure fluctuations and layer discontinuities. These structure disorders may result in serious parameter losses by producing of shunt interconnections or other charge flow parasitic effects. Taking into account cadmium dichloride dissolvent presence frequently caused by recrystallization demands .
