| Summary: | 碩士 === 國立中正大學 === 機械工程所 === 96 === This study investigates the influence of the metal oxide nanopowders (MONPs), TiO2 and ZnO, and the porous TiO2 layer on the performance of a bulk- heterojunctioned solar cell. To probe the individual effects of the TiO2 layer and the MONPs, this study is proceeded along with the following 5 continuing designed devices: (1) the device with a single polymer layer sandwiched by two electrodes, ITO/MEH-PPV/Al; (2) the bi-layered device using MEH-PPV as donor and MONPs as acceptor, ITO/MEH-PPV/MONPs/Al; (3) the bi-layered device with a porous TiO2 layer, ITO/Porous TiO2/MONPs/MEH-PPV/Au; (4) the device with a bulk heterojunction layer of MEH-PPV as donor and MONPs as acceptor and sandwiched by two electrodes, ITO/MEH-PPV+MONPs/Al; and, (5) the device with the basic structure as in (4) but including a porous TiO2 layer, ITO/porous TiO2/MEH-PPV+ MONPs/Al. Besides serving as supplementary experiments for allocating appropriate fabrication parameters, the study on Device (1), (2) and (4) also indicts the device efficiency is increased as the studied order. The porous TiO2 layer, calcined from the titanium tetraisopropoxide (TTIP) solution mixing with the block copolymer, polystyrene-block-polyisoprene (PS-b-PI), can form interconnected paths for carrier transportation and thus improved the device performance. However, through the same porous structure, polymer solution is able to penetrate to the electrode as well and a hole-blocking layer above the electrode is usually required. With the device structure we proposed for Device (3), in addition to its designated role as an acceptor, the MONPs exhibits the function as partially preventing the infiltration of polymer solution and leading to an increase of device efficiency from 0.035% to 0.1%. For a general bulk heterojuction device, the carrier transportation path is discontinuous. With the incorporation of the porous TiO2 layer in Device (5), this problem can be greatly improved and a dramatically efficiency enhancement from 0.02% to 0.1% is obtained.
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