Hybrid morphology dependence of CdTe:CdSe bulk-heterojunction solar cells
- PDF / 2,384,235 Bytes
- 8 Pages / 595.276 x 793.701 pts Page_size
- 95 Downloads / 232 Views
NANO EXPRESS
Open Access
Hybrid morphology dependence of CdTe:CdSe bulk-heterojunction solar cells Furui Tan1, Shengchun Qu2*, Weifeng Zhang1 and Zhanguo Wang2
Abstract A nanocrystal thin-film solar cell operating on an exciton splitting pattern requires a highly efficient separation of electron-hole pairs and transportation of separated charges. A hybrid bulk-heterojunction (HBH) nanostructure providing a large contact area and interpenetrated charge channels is favorable to an inorganic nanocrystal solar cell with high performance. For this freshly appeared structure, here in this work, we have firstly explored the influence of hybrid morphology on the photovoltaic performance of CdTe:CdSe bulk-heterojunction solar cells with variation in CdSe nanoparticle morphology. Quantum dot (QD) or nanotetrapod (NT)-shaped CdSe nanocrystals have been employed together with CdTe NTs to construct different hybrid structures. The solar cells with the two different hybrid active layers show obvious difference in photovoltaic performance. The hybrid structure with densely packed and continuously interpenetrated two phases generates superior morphological and electrical properties for more efficient inorganic bulk-heterojunction solar cells, which could be readily realized in the NTs:QDs hybrid. This proved strategy is applicable and promising in designing other highly efficient inorganic hybrid solar cells. Keywords: Hybrid bulk-heterojunction solar cells; CdSe; CdTe
Background Solar cells based on nanoparticles have attracted intense attention in view of their compatibility with the solution synthesis of materials, low-cost fabrication of devices, and large area flexibility. Compared with their counterparts of organic solar cells which also possess these potentials, nanocrystal thin-film solar cells offer easy tuning of light response in a broad range by tuning the quantum size effect of colloidal nanoparticles. Up to now, tremendous attention has been paid to photovoltaic nanomaterials which could be adopted in thin-film solar cells, such as PbS [1-4], CuInS2 [5-7], and CdTe [8,9]. With regard to the presently researched photovoltaic device with Schottky contact or bilayer heterojunction structure, it was suggested that the photocurrent was generated from charge separation driven by the built-in electric field in the depletion region which is located at the semiconductor-metal contact [10,11] or p-n interface [12,13]. Photogenerated excitons must diffuse a long way to the p-n depletion region before their splitting, which * Correspondence: [email protected] 2 Key Laboratory of Semiconductor Materials Science, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, People’s Republic of China Full list of author information is available at the end of the article
takes a high risk of recombination considering a relatively large quantum dot (QD) thickness as well as a small depletion width. To resolve this problem, a hybrid bulkheterojunction (HBH) nanostructure was adopted [14], as what is commonly used in org
Data Loading...
