ENGINEERING THE MICROSTRUCTURE AND CHEMISTRY OF BOTH QUANTUM DOTS AND PHOTOANODES IN QUANTUM-DOT SENSITIZED SOLAR CELLS FOR HIGH POWER CONVERSION EFFICIENCY

摘要

Quantum dot-sensitized solar cells (QDSCs) as a derivative ofndye-sensitized solar cells (DSCs) have attracted considerablenattention and been regarded as a promising alternative tonconventional solid-state semiconductor solar cells. QDSCs arenrelatively cost-effective and easy to manufacture, and furthermore,ncompared to organic dyes, narrow band gap semiconductor QDsnpossess multiple extraordinary optical and electrical properties innterms of (1) tunable band gap across a wide energy range, (2) strongnlight absorption, (3) high stability against oxidative deterioration, (4)nhigh extinction coefficients, and (5) large intrinsic dipole momentnfacilitating charge separation. A high theoretical photovoltaicnconversion efficiency up to 44% in view of the multiple excitationngeneration (MEG) effect, beyond the traditional Shockley andnQueisser limit of 32% for semiconductor solar cell, has encouragednpeople to develop QDSCs with the use of CdS, CdSe, CdTe, PbS,nand Ag2S QDs, as sensitizers for light harvesting.