CuInSe2-based micro-concentrator solar cells fabricated from In islands grown by laser-assisted MO-CVD

Micro-concentrator solar cells offer a promising route for reducing material usage in photovoltaics. For Cu(In,Ga)Se 2 , multiple micro-concentrator manufacturing methods have already been evaluated. All of them involve either high preparation complexity or post-processing to recycle unused precursor or absorber materials. In this work, a new method using laser-assisted metal-organic chemical vapor deposition (LA-MOCVD) was applied to directly grow arrays of indium micro-islands. These arrays are examined and further processed to CuInSe 2 micro-solar cell arrays. The geometry and morphology of the islands were investigated and compared before and after absorber formation. The investigation shows that the absorber growth is limited to the vertical direction normal to the substrate surface and that the starting morphology is preserved. Furthermore, the absorber island arrays are processed into micro-modules and operational solar cells are achieved as a proof of principle. These not yet optimized arrays reach a conversion efficiency of 0.65% under 1 sun illumination. Under 17 suns of light concentration, the efficiency gain is between 60 and 250%. This work demonstrates the method's viability for the fabrication of micro-solar cell arrays, with clear potential for achieving higher conversion efficiencies through future optimization. • Laser-assisted local growth of multiple indium precursor islands. • Simultaneous grown 49 sub-cell containing micro-concentrator modules. • 250% relative efficiency boost under 17 suns concentrated irradiation.