Using high haze (>90%) light-trapping film to enhance the efficiency of a-Si:H solar cells

• Published in: Optics communications Vol. 285; no. 15; pp. 3325 - 3328
• Main Authors: Chu, Wei-Ping, Lin, Jian-Shian, Lin, Tien-Chai, Tsai, Yu-Sheng, Kuo, Chen-Wei, Chung, Ming-Hua, Hsieh, Tsung-Eong, Liu, Lung-Chang, Juang, Fuh-Shyang, Chen, Nien-Po
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.07.2012
• Subjects: a-Si:H thin film solar cells; Density; Glass; Glues; Haze; Imprint; Light trapping film; Photovoltaic cells; Scattering; Short circuit currents; Solar cells; a-Si:H thin film solar cells; Light trapping film; Haze; Imprint
• ISSN: 0030-4018; 1873-0310
• DOI: 10.1016/j.optcom.2012.02.088

The high haze light-trapping (LT) film offers enhanced scattering of light and is applied to a-Si:H solar cells. UV glue was spin coated on glass, and then the LT pattern was imprinted. Finally, a UV lamp was used to cure the UV glue on the glass. The LT film effectively increased the Haze ratio of glass and decreased the reflectance of a-Si:H solar cells. Therefore, the photon path length was increased to obtain maximum absorption by the absorber layer. High Haze LT film is able to enhance short circuit current density and efficiency of the device, as partial composite film generates broader scattering light, thereby causing shorter wave length light to be absorbed by the P layer so that the short circuit current density decreases. In case of lab-made a-Si:H thin film solar cells with v-shaped LT films, superior optoelectronic performances have been found (Voc=0.74V, Jsc=15.62mA/cm2, F.F.=70%, and η=8.09%). We observed ~35% enhancement of the short-circuit current density and ~31% enhancement of the conversion efficiency.