Simulation of Interdigitated Back Contact Solar Cells and Experimental Analysis of Emitter Recombination Current
Date Issued
2015
Date
2015
Author(s)
Tsai, Zheng-Gang
Abstract
In this thesis, the characteristics of emitter of n-type Si-based solar cells are investigated and the enhancements of n-type Si-based interdigitated back contact (IBC) solar cells are also studied. The goals of this thesis are to optimize the parameter of solar cells by numerical simulations using technology computer aided design (TCAD) simulator to provide concepts to improve the performances of cells. Firstly, we vary the surface recombination velocity (SRV), the bulk lifetime and emitter ratio. Then, we simulate the process of the ion implantation by numerical simulators using TCAD simulator and optimize the parameter in the fabrication, such as the implanted dose and annealing temperature. Secondly, we combine the advantages of IBC solar cells and heterojunction with intrinsic thin films (HIT) solar cells to get the higher efficiency of solar cells, called interdigitated back contact silicon heterojunction (IBC-SHJ) solar cells. To optimize the efficiency, we simulate the design of the structure and the bandgap of p, i and n-type amorphous Si layers by using TCAD simulator. Finally, we discuss the characteristics in the emitter of n-type Si-based solar cells. A p+/n/p+ symmetrical structure is fabricated by ion implantation tool. We measure it to analyze the characteristics of the emitter by means of Quasi-Steady-State Photo-conductance (QSSPC) method. It is helpful to improve the efficiency of solar cells by using the appropriate annealing condition and the optimized wet chemically etching condition since the damage is introduced by ion implantation process.
Subjects
heterojunction
interdigitated back contact solar cells
ion implantation
emitter saturation current
quasi-steady-state photo-conductance
thermal annealing
Type
thesis