tailieunhanh - Báo cáo hóa học: " Facile solution growth of vertically aligned ZnO nanorods sensitized with aqueous CdS and CdSe quantum dots for photovoltaic applications"

Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Facile solution growth of vertically aligned ZnO nanorods sensitized with aqueous CdS and CdSe quantum dots for photovoltaic applications | Luan et al. Nanoscale Research Letters 2011 6 340 http content 6 1 340 o Nanoscale Research Letters a SpringerOpen Journal NANO EXPRESS Open Access Facile solution growth of vertically aligned ZnO nanorods sensitized with aqueous CdS and CdSe quantum dots for photovoltaic applications z Z-I Chunyan Luan Aleksandar Vaneski Andrei S Susha Xueqing Xu Hong-En Wang Xue Chen Jun Xu Wenjun Zhang1 2 Chun-Sing Lee1 2 Andrey L Rogach1 3 and Juan Antonio Zapien1 2 Abstract Vertically aligned single crystalline ZnO nanorod arrays approximately 3 pm in length and 50-450 nm in diameter are grown by a simple solution approach on a Zn foil substrate. CdS and CdSe colloidal quantum dots are assembled onto ZnO nanorods array using water-soluble nanocrystals capped as-synthesized with a short-chain bifuncional linker thioglycolic acid. The solar cells co-sensitized with both CdS and CdSe quantum dots demonstrate superior efficiency compared with the cells using only one type of quantum dots. A thin Al2O3 layer deposited prior to quantum dot anchoring successfully acts as a barrier inhibiting electron recombination at the Zn ZnO electrolyte interface resulting in power conversion efficiency of approximately 1 with an improved fill factor of . The in situ growth of ZnO nanorod arrays in a solution containing CdSe quantum dots provides better contact between two materials resulting in enhanced open circuit voltage. Introduction As an n-type semiconductor with a direct and wide bandgap of eV ZnO is an attractive material for a variety of applications ranging from ultraviolet lasers 1 and sensors 2 to field-emission devices 3 . In recent years vertically aligned one-dimensional ZnO nanostructures have gained great interest for dye-synthesized solar cells 4 5 as a promising alternative to mesoporous TiO2 films 6 . Both ZnO and TiO2 have similar bandgaps while the higher electron mobility and direct electrical pathways provided by