Dependence of electrical and structural properties on the thickness of n-type μc-Si thin-film silicon solar cells grown by linear facing target sputtering

Abstract

In this work, the construction of an (Al+Ag)/n⁺-Si/p-Si/Al thin-film silicon (TF-Si) solar cell is presented. The maximum achievable current density generated by a planar solar cell, with an optimum antireflection coating, for different values of the cell thickness are analysed. Both electrical and optical properties of (Al+Ag)/n⁺-Si/p-Si/Al TF-Si solar cell have been studied, which assumes the generation of one electron–hole pair per photon and a collection efficiency of unity. A reduction in thickness can lead to an increase in V_OC, it can have the opposite effect if surface recombination is not reduced simultaneously. Thin-film solar cell has an absorbed photon flux density about three times higher at each interface, implying that carrier generation at the interfaces of the thinner cell is about three times higher. Finally, for larger grain size, the recombination at the grain boundaries (GBs) of Si will mainly degrade V_OC, and not J_SC. From the obtained results, it is evident that the larger the grain size, the better the performance of the device. However, the interface recombination has a strong influence on each parameter.

Keywords:

• thin-film silicon solar cells
• effect of thickness
• electrical characteristics
• surface texture
• surface-recombination velocities
• grain boundaries