Fabrication of CdSe sensitized SnO2 nanofiber quantum dot solar cells

In the present study, we report a cost-effective quantum dot solar cells based on a combination of electrospinning and successive-ionic-layer-adsorption and reaction (SILAR) methods. CdSe nanocrystals are deposited on electrospun SnO2 nanofibers by SILAR method using CdCl2 as the cadmium source and Na2Se as selenium source. The as-prepared materials are characterized by spectroscopy and microscopy. CdSe deposited SnO2 electrodes are also characterized by spectroscopy and microscopy. Cells are fabricated with platinum (Pt)-sputtered FTO glasses used as the counter electrodes and polysulfide solution used as the electrolyte. The efficiency of the cells is studied for different number of SILAR cycles. Current density–voltage (J–V) measurements on a cell having CdSe deposition of 7 SILAR cycles and SnO2 coating area 0.25 cm2 showed an overall power conversion efficiency of 0.29 % with a photocurrent density (JSC) of 5.32 mA cm−2 and open circuit voltage (VOC) of 0.23 V under standard 1 Sun illumination of 100 mWcm−2 (AM 1.5 G conditions). This is improved by carefully coating SnO2 film without losing the structures. Also ZnS passivation layer is coated to obtain an improved efficiency of 0.48% with JSC of 4.68 mAcm−2, and VOC of 0.43 V.