Simulation Study On μc - Si: H (n) / C - Si (p) Heterojunction Solar Cells

Solar energy is a kind of inexhaustible and environment friendly resources. How to effectively use solar energy in daily life is a problem that people care about. In recent years, the research of solar cells has achieved some results. The emergence of this new type of HIT solar cell structure, with its high efficiency and low costs quickly get industry recognition.Firstly, this paper analyzes the influence of thickness and band gap of μc-Si:H(n) emitter layer, a-Si:H(i) front and back intrinsic layer and μc-Si:H(p+) back surface field on the performance of μc-Si:H(n)/a-Si:H(i)/c-Si(p)/ a-Si: H(i)/ μc-Si:H(p+) solar cell through using AFORS-HET software. These simulation results showed that solar cell generated highest efficiency at μc-Si:H(n) emitter layer thickness of 6nm and band gap of 1.6eV, a-Si:H(i) front and back intrinsic layers thickness of 3nm and band gap of 1.6eV respectively, and μc-Si:H(p+) back surface field thickness of 10 nm and band gap of 1.4eV.On the basis of the above, next we analyzes the influence of front TCO/μcSi:H(n) contact on the performance of μc-Si:H(n)/a-Si:H(i)/c-Si(p) HIT solar cell, the influence of back TCO/μc-Si:H(p+) contact and different TCO materials as a plant and a texture on the performance of TCO/μc-Si:H(n)/ a-Si:H(i)/c-Si(p)/a-Si:H(i)/μc-Si:H(p+)/TCO bifacial solar cell. These simulation results showed that the use of TCO can further improve the performance of solar cells and the textured TCO structure was better the plant TCO structure on the solar cell.Finally we present analyses of how and why band offsets of μc-Si:H(n) /c-Si(p) interface and band offsets of c-Si(p)/μc-Si:H(p+) do affect the carrier transport properties and quality which influence the performance of solar cell. When the conduction band offset at μc-Si:H(n)/c-Si(p) interface was under 0.3 e V, and the conduction band offset at c-Si(p)/BSF interface for the back surface field(BSF) was about 0.25 eV, the photoelectric conversion efficiency of the textured TCO/μc-Si:H(n)/a-Si:H(i)/c-Si(p)/a-Si:H(i)/μc-Si:H(p+)/TCO solar cell could reach 24.43%, and Voc: 775 mV,Jsc: 42.03mA/cm2, FF:75% by simulation. This indicates that further research the interfaces transport mechanisms of solar cell can improve the interfaces transport quality and efficiency of solar cell.