화학공학소재연구정보센터
Applied Surface Science, Vol.494, 551-560, 2019
Enhancing the power conversion efficiency of SrTiO3/CdS/Bi2S3 quantum dot based solar cell using phosphor
The role of down-conversion phosphorescence in the enhancement of power conversion efficiency (PCE) of TiO2: SrTiO3/CdS/Bi2S3/ZnS: Cu heterostructure solar cell is reported here. ZnS:Cu is used as phosphor which converts a fraction of the ultra violet energy to visible range, increasing the light harvesting capacity. Also this acts as a passivation layer, to reduce the charge recombination. SrTiO3 nanoparticles with spherical morphology were synthesized by co-precipitation technique and CdS, Bi2S3 and ZnS: Cu were grown on the SrTiO3 by successive ionic layer adsorption and reaction (SILAR) method after optimizing the Cu concentration. The structural, morphological and composition were studied by XRD, SEM, TEM and XPS measurements. J-V measurements of TiO2: SrTiO3/CdS/Bi2S3/ZnS: Cu-3 structure based solar cell are done by solar simulator under 1.5 AM and found to exhibit an enhancement in PCE to the tune of 55% than SrTiO3/CdS/Bi2S3 (pristine) based solar cell. Incident Photon Current Efficiency (IPCE) spectrum covered a spectral range of 400 to 900 nm for TiO2: SrTiO3/CdS/Bi2S3/ZnS: Cu-3 cell with the maximum IPCE similar to 51%. Electrochemical impedance analysis is also carried out in the form of Nyquist and Bode phase plots for the fabricated solar cells which possess low values of Rs, Rct and longer life time for the charge carriers which is favorable for higher PCE.