Continuous-wave photoinduced absorption study on trapped carriers in bulk-heterojunction solar cells connected to load

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• 作者：Yosuke Terada ; Takashi Kobayashi ; Emi Nakatsuka ; Takashi Nagase ; Hiroyoshi Naito
• 关键词：Bulk-heterojunction solar cells ; Trap ; Operating points ; Photoinduced absorption spectroscopy ; Carrier transport
• 刊名：Thin Solid Films
• 出版年：3 March, 2014
• 年：2014
• 卷：554
• 期：Complete
• 页码：209-212
• 全文大小：404 K

文摘

By using continuous-wave photoinduced absorption spectroscopy, we investigate hole-transport processes in polymer-based bulk-heterojunction solar cells at various operating points between the open- and short-circuit conditions. The results reveal that the detrapping time constant of holes decreases as the short-circuit condition is approached. This decrease may be explained by an acceleration of detrapping that is caused by an internal electric field. This interpretation is supported by a numerical simulation based on rate equations, considering a low density of a single trap level. Since the detrapping signal disappears at short-circuit, we estimate the associated trap levels to be relatively shallow.