Record High Efficiency Single-Walled Carbon Nanotube/Silicon p-n Junction Solar Cells
Record High Efficiency Single-Walled Carbon Nanotube/Silicon p-n Junction Solar Cells
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DOI：
10.1021/nl3035652
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发表时间：
2013-01-01
期刊：
影响因子：
10.8
通讯作者：
Reed, Mark A.
中科院分区：
文献类型：
--
作者：
Jung, Yeonwoong;Li, Xiaokai;Reed, Mark A.
研究了高效单壁碳纳米管（SWNTs）/硅（Si）异质结太阳电池的载流子输运特性。太阳能电池是通过在n型Si晶片上沉积本征p型SWNT薄膜而制造的，而不涉及任何高温过程以形成p-n结。优化的电池显示出接近1的器件理想因子和> 11%的创纪录高功率转换效率。通过研究暗正向电流密度随温度变化的特性，我们已经确定，温度相关的电流整流源于热激活的带-带跃迁的载流子在Si中，和单壁碳纳米管薄膜的作用是建立一个内置的潜在的载流子分离/收集。我们还建立了主要的载流子传输机制是扩散，与最小的界面复合。这是进一步支持了类似于34 μ s，由瞬态恢复方法确定的一个长的少数载流子寿命的观察。这项研究表明，这些混合型太阳能电池的工作方式与单晶p-n同质结硅太阳能电池相同。
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-n 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 similar to 34 mu s, determined by the transient recovery method. This study suggests that these hybrid solar cells operate in the same manner as single crystalline p-n homojunction Si solar cells.