Advanced Functional Materials: Intrinsic and Doped Silicon Oxide
- PDF / 3,229,341 Bytes
- 6 Pages / 612 x 792 pts (letter) Page_size
- 5 Downloads / 207 Views
Advanced Functional Materials: Intrinsic and Doped Silicon Oxide Xiaodan Zhang*, Bofei Liu, Lisha Bai, Fang jia, Shuo Wang, Qian Huang, Jian Ni, Changchun Wei, Dekun Zhang, Jian Sun, Xinliang Chen, Huizhi Ren, Guofu Hou, Shengzhi Xu, Guangcai Wang, and Ying Zhao Institute of Photo Electronics thin Film Devices and Technology of Nankai University, Key Laboratory of Photoelectronic Thin Film Devices and Technology, Tianjin 300071, P. R. China Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin 300072, China ABSTRACT The unique properties of silicon oxide materials, no matter intrinsic or doped, utilized in thin film solar cells (TFSCs) in the area of photovoltaic (PV) are making TFSCs one of the most attractive photovoltaic technologies for the development of high-performing electricity production units to be integrated in everyday life. In comparison to other silicon materials, the particular diphasic structure of silicon oxide materials, in which hydrogenated microcrystalline silicon (μc-Si:H) crystallites are surrounded by an oxygen-rich hydrogenated amorphous silicon (a-Si:H) phase, causes them present excellent photoelectrical material properties, such as a lowparasitic absorption in the broadband spectral range, independent controllability of longitudinal and lateral conductivity, refractive indices (3.5-2.0), band gap (2.0-2.6 eV) and conductivity tenability (with orders of 1-10-9 S/cm) with oxygen doping, and so on. Various types of silicon oxide materials, including intrinsic, p- or n- type, further applied in TFSCs have also played significant roles in improving the efficiency of various types of single-, dual-, and triple-junction thin-film solar cells from both the optical and electrical points of view. In this paper, we present our latest progress in studying the performance improvement role of intrinsic or doped silicon oxide materials in pin-type a-Si:H, a-SiGe:H, and μc-Si:H single-junction solar cells. By effectively tuning the band gap values of intrinsic a-SiOx:H materials with oxygen doping and adopting the layers with a suitable band gap (1.86 eV) as the P/I buffer layers of a-Si:H solar cells fabricated on metal organic chemical vapor deposition (MOCVD) boron-doped zinc oxide (ZnO:B) substrates, a significant Voc increases up to 909 mV and an excellent external quantum efficiency (EQE) response of 75% at the 400 nm typical wavelength can be achieved by matching the band gap discontinuity between the p-type nc-SiOx:H window and a-Si:H intrinsic layers. The serious leakage current characteristics of pin-type narrow-gap (Eg0.5). Therefore, the
maximum FF was obtained for the narrow-gap a-SiGe:H single-junction solar cell with a n-type μc-SiOx:H layer deposited with a low CO2/SiH4 ratio of 0.5. In summary, the insertion of n-type μc-SiOx:H layer was found to promote the increase of FF of a-SiGe:H single-junction solar cells. Table II. J-V characteristics of a-SiGe:H single-junction solar cells with deposited with different CO2/SiH4 ratios from 0 to 2. Jsc Jsc>530n
Data Loading...
