Designing band offset of a-SiO:H solar cells for very high open-circuit voltage (1.06V) by adjusting band gap of p-i-n junction

作者：Hishida Mitsuoki^*; Sekimoto Takeyuki; Terakawa Akira

来源：Japanese Journal of Applied Physics, 2014, 53(9): 092301.

DOI：10.7567/JJAP.53.092301

We have matched the world's highest open-circuit voltage (V-oc: 1.06 V) achieved to date for a layered structure comprised of a glass/tin oxide (SnO2)/hydrogenated amorphous silicon oxide (a-SiO:H) (p-i-n)/back electrode. For the purposes of this study, we adjusted the band gaps of each layer (p-i-n) to improve overall film quality. Fine-tuning of band profiles with reference to activation energy and optical band gap allowed us to offset the conduction band and the valence band of each layer (p-i-n) and thus improve the built-in potential rather than the electron conductivity, Fourier transform infrared spectroscopy, transmittance or reflectance ratio, resulting in a high V-oc. To fully exploit the characteristics of wide-bandgap materials and prevent problems with absorbance, we employed commercially available SnO2 in the front transparent conductive oxide instead of zinc oxide. Using our deposition and evaluation technologies to build a wide-band-gap single solar cell, we succeeded in matching the world's highest V-oc of 1.06 V (Eff: 5.38%, J(sc): 8.15 mA/cm(2), FF: 0.624).

• 出版日期2014-9