Research Of Solar Cells Based On Copper Phthalocyanine

With high-speed development of economy, energy problems have become the most vital obstacle to development all over the world. Solar energy that is over 99% of total energy on the earth, have gained a great deal of attention by scientists due to its many merits, such as safety, disbefouling environment, and extremely excessive amount, et al. In recent years, solar cells have attracted considerable interest because they are one of the most important ways to utilize sloar energy, and the research of sloar cells has made great progress. At present, research of solar cells mainly focus on improving the power conversion efficiency and reducing the costs.Copper phthalocyanine (CuPc) has been used extensively as electron donor in organic solar cells due to its marked photovoltaic effect and photoconductivity characteristics. So far, the power conversion efficiency of organic solar cell based on CuPc have been achieved 5.58% in laboratory. However, low power conversion efficiency is still a major obstacle to the device application. Therefore, efforts to improve the photovoltaic properties of solar cell based on CuPc is still needed to made.In this thesis, we aimed at research of solar cells based on copper phthalocyanine, and carried out beneficial exploration in the following three aspects mainly:1. Three different bulk heterojunction solar cells have been fabricated using the poly (2-methoxy-5-(2'-ethyl-hexyloxy)-1,4-phenylene vinylene) (MEH-PPV) and copper phthalocyanine (CuPc) as electron donors, and with 1-(3-methoxycarbonyl)-propyl-1-1-phenyl-(6,6) C61 (PCBM) as electron acceptor. Dramatically increased absorption spectra coverage was achieved by doping the CuPc to the blended films of MEH-PPV and PCBM, which improved the ability of absorbing the photons. The incorporation of CuPc showed further PL intensity quenching due to the separation of the photo-generated charges. Further, the current-voltage characteristics showed that the performance of cells achieved the best one when the CuPc approaches to 50% in weight compared with that of the MEH-PPV.2. Hybrid solar cell based on CuPc and n-Si with textured structure has been fabricated. Effects of texturization on the performance of CuPc/n-Si hybrid solar cell was discussed. Moreover, Electrochemical Impedance Spectroscopy (EIS) has been used to analyze charge carrier transport mechanism of solar cell. The equivalent circuit model consisting of a parallel resistor and capacitor in series with a resistor gives a good fit to the experimental data, which is applicable to cell's structure. The conduction mechanism was suggested to be a space-charge limited current with exponential trap distribution.3. Well-aligned ZnO nanorod array, synthesized by wet chemical bath deposition (CBD) method on conductive indium-tin-oxide (ITO) substrate. Surface photovoltage (SPV) technique based on a scanning Kelvin Probe system was employed to investigate the optoelectronic behavior of ZnO nanorod array. The surface photovoltage and its time-resolved evolution process are used to determine the energy level structure of the ZnO nanorod array. Kelvin Probe technique also was used to study the photovoltaic properties of the copper-phthalocyanine (CuPc), and CuPc/ ZnO nanorod array system. Moreover, Surface photovoltage (SPV) technique based on a lock-in amplifier was employed to study the photovoltaic properties of the copper-phthalocyanine (CuPc) and ZnO nanorod array system affected by ethanol. Several useful results and experience were obtained, which will benefit practical photoelectric applications based on ZnO nanorods and CuPc.