Record High Efficiency Single-Walled Carbon Nanotube/Silicon p鈥?/i>n Junction Solar Cells
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- 作者：Yeonwoong Jung ; Xiaokai Li ; Nitin K. Rajan ; Andr茅 D. Taylor ; Mark A. Reed
- 刊名：Nano Letters
- 出版年：2013
- 出版时间：January 9, 2013
- 年：2013
- 卷：13
- 期：1
- 页码：95-99
- 全文大小：287K
- 年卷期：v.13,no.1(January 9, 2013)
- ISSN：1530-6992
文摘
Carrier transport characteristics in high-efficiency single-walled carbon nanotubes (SWNTs)/silicon (Si) hybrid solar cells are presented. The solar cells were fabricated by depositing intrinsic p-type SWNT thin-films on n-type Si wafers without involving any high-temperature process for p鈥搉 junction formation. The optimized cells showed a device ideality factor close to unity and a record-high power-conversion-efficiency of >11%. By investigating the dark forward current density characteristics with varying temperature, we have identified that the temperature-dependent current rectification originates from the thermally activated band-to-band transition of carriers in Si, and the role of the SWNT thin films is to establish a built-in potential for carrier separation/collection. We have also established that the dominant carrier transport mechanism is diffusion, with minimal interface recombination. This is further supported by the observation of a long minority carrier lifetime of 34 渭s, determined by the transient recovery method. This study suggests that these hybrid solar cells operate in the same manner as single crystalline p鈥搉 homojunction Si solar cells.