Guo Min, Yang Lu, Chen Jia, Zhang Jun, Su Haijun, Liu Lin, Xie Keyu
State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi'an 710072, China.
J Nanosci Nanotechnol. 2018 Dec 1;18(12):8337-8344. doi: 10.1166/jnn.2018.16387.
The relatively small electron diffusion coefficient and high charge recombination rate of TiO2 nanoparticle (NP) film limit charge collection in TiO2 NP based dye-sensitized solar cells (DSSCs). Herein, ultralong bending TiO2 (B) nanowires (NWs) were introduced to TiO2 NP photoanode and expected to modify electron transport of DSSCs. The TiO2 (B) NWs/TiO2 NP composite structure was prepared by a facial process combining the stirring hydrothermal method with mechanical mixing method. When the composite structure was applied to DSSCs, the rapid electron transport pathway was formed in photoanode, which was clarified by the small electron transport resistance and long electron diffusion length, improving the charge collection efficiency. Moreover, the scattering effect of TiO2 (B) NWs could enhance the light harvesting, and thus improve the power conversion efficiency (PCE) of DSSCs. The excellent electronic and optical characteristics of TiO2 (B) NWs yield the maximum enhancement of PCE (36.4%) when 50% (wt.%) TiO2 (B) NWs was integrated into TiO2 NP based DSSC. The work provides new insights into the design and tailoring nanowires to enhance the PCE of DSSCs for practical applications.
二氧化钛纳米颗粒（NP）薄膜相对较小的电子扩散系数和较高的电荷复合率限制了基于二氧化钛NP的染料敏化太阳能电池（DSSC）中的电荷收集。在此，将超长弯曲的二氧化钛（B）纳米线（NWs）引入到二氧化钛NP光阳极中，期望改善DSSC的电子传输。通过搅拌水热法与机械混合法相结合的简便工艺制备了二氧化钛（B）NWs/二氧化钛NP复合结构。当将该复合结构应用于DSSC时，在光阳极中形成了快速电子传输路径，这通过小的电子传输电阻和长的电子扩散长度得以阐明，提高了电荷收集效率。此外，二氧化钛（B）NWs的散射效应可以增强光捕获，从而提高DSSC的功率转换效率（PCE）。当将50%（重量%）的二氧化钛（B）NWs集成到基于二氧化钛NP的DSSC中时，二氧化钛（B）NWs优异的电子和光学特性使PCE得到最大增强（36.4%）。这项工作为设计和定制纳米线以提高DSSC在实际应用中的PCE提供了新的见解。
