Document Type : Research Article

Authors

• Atabek Atamuratov ¹
• Bekhzod Jumaboev ¹
• Ahmed Yusupov ²
• Eldor Khaitboev ¹
• Makhkam Khalilloev ¹
• Jean Chamberlain Chedjou ³

¹ Physics department, Urgench State University, P.O. Box: 220100, Urgench, Uzbekistan.

² Department of Electronics and Radiotechnics, Tashkent University of Information Technologies, P.O. Box: 200100, Tashkent, Uzbekistan.

³ Institute of Smart Systems Technologies, University of Klagenfurt, P.O. Box: 9020, Klagenfurt, Austria.

Abstract

In this work, the modelling of a two-junction vertical silicon solar cell is presented. The primary focus is on comparing the characteristics and performance parameters of the device when either a tunnel junction or a metallic layer is employed as the interconnect between the subcells. The advantages and limitations of fabrication technologies for vertical solar cells incorporating either a tunnel junction or a metallic interlayer as the inter-subcell contact are discussed. For the tunnel-junction-based structure, the simulation framework and set of parameters used in the modeling are described in detail. By fitting the simulated and experimental I-V characteristics of the tunnel junction, the following parameters were extracted: the effective masses at the band edges mc=0.212m0, mv=0.178m0, as well as the Huang–Rhys factor S=1.29. Comparative results for the dependence of conversion efficiency on solar concentration are also presented. It is shown that, for the considered geometrical dimensions, the efficiency differences between the analyzed device configurations are minimal. For both types of solar cells, the conversion efficiency increases approximately linearly with solar concentration up to approximately 200 suns, reaches a saturation region, and then begins to decrease at concentrations exceeding approximately 500 suns.

Keywords

• Silicon tunnel junction
• two junctions solar cell
• vertical solar cell
• efficiency of solar cell
• fill factor