Xiong Chao

Photovoltage analysis of a heterojunction solar cell

According to the p—n junction model of Shockley, the relationship between the equilibrium carrier concentrations of n-type and p-type semiconductors on the edges of the depletion region of a p—n junction solar cell is analysed. The calculation results show that the photovoltage can exceed the built-in voltage for a special kind of heterojunction solar cell. When the photovoltage exceeds the built-in voltage under illumination, the dark current and the photocurrent are impeded by the peak of voltage barrier at the interface and the expression of the total I—V characteristic is given.

Study on the Synthesis, Characterization of p-CuSCN/n-Si Heterojunction

The p-CuSCN/n-Si heterojunction is fabricated by depositing CuSCN films on n-Si (111) films substrate using successive ionic layer adsorption and reaction (SULAR). CuSCN films show ufffb -phase structure by virtue of X-ray diffraction (XRD) spectroscopy. ZnO/CuSCN heterojunctions exhibit good diode characteristics and photovoltaic effects with illumination form its current-voltage (I-V) measurements. The linear relationship of 1/C 2 versus voltage curve implies that the built-in potential Vbi and the conduction band offset of the heterojunctions were found to be 2.1eV and 1.5eV, respectively. The forward conduction is determined by trap-assisted space charge limited current mechanism. At forward bias voltages, the electronic potential barrier is larger than holes in the p-CuSCN/n-Si heterojunction interface. In this voltage area, a single carrier injuction is induced and the main current of p-CuSCN/n-Si heterojunction is hole current. In addition, a band diagram of ZnO/CuSCN heterojunctions is also proposed to explain the transport mechanism. This heterojunction diode can be well used to light emission devices and photovoltaic devices.