Fabrication And Performance Study Of Bilayer Heterojunction Photovoltaic Device Based On PANI/Nd₂O₃

Energy problem is an important issue all over the world in the21st century. And solar energy is inexhaustible, clean, cheap energy that mankind can use free. In recent years, polymer solar cell has became the public focus because of polymer’s many virtue, such as low cost, light weight, and easy synthesized. This thesis is about fabrication and performance of bilayer heterojunction photovoltaic device based on PANI/Nd2O3.Aniline monomer, doped reagent of toluene-p-sulfonic acid and oxidant of ammonium superphosphate were used to synthesize conducting polyanline (PANI) nanofibers by chemical oxidation technology. Four points probes method was used to test the conductivity of PANI in room temperature, SEM experiment was used to characterize PANI.Pt electrodes modified by the PANI nanofibers film (expressed as PANI/Pt) were prepared through the method of in-situ polymerization. According to the cyclic voltammetry (CV) cuver of PANI/Pt in H2SO4of0.1mol·L-1and the UV-Vis absorption curve of PANI in N, N-dimethylformamide, the energy band structure of PANI has been calculated, and the energy levels of highest occupied orbital (EHOMO) is-4.84eV, the lowest empty orbital (ELUMO) is-3.29eV, the width of energy gap (Eg) is1.55eV, respectively. These results show that the energy gap of PANI is smaller than the average energy of solar light. Therefore the PANI synthesized in the thesis could be appllied in photoelectric conversion device.Solvent evaporation technique has been used to manufacture single layer devices PANI/ITO (ITO coated by PANI) and Nd2O3/ITO (ITO coated by Nd2O3). Then a bilayer heterojunction photovoltaic device ITO/PANI/Nd2O3/ITO was assembled with these two kinds of single layer devices. I-U characteristic curve and loaded curve of ITO/PANI/Nd2O3/ITO had been tested. Open-circuit voltage (Uoc), short circuit current (ISC) and fill factor (FF) were calculated:UOC=145mV,ISC=42μA, FF=36%.Some influencing factors on the device’s performence were studied. The results show that Isc value rises gradually with increasing of sintering temperature of Nd2O3. Luminous intensity shows linear relationship with either short circuit current (ISC) or the natural logarithm of open circuit voltage (lnUOC).The photovoltaic device shows high UOC,ISC and FF values when the polymerization time of PANI is16h.