Dong Chan Lim

Development of Inverted Organic Photovoltaics with Anion doped ZnO as an Electron Transporting Layer

In this study, 3-dimensional ripple structured anion (chlorine) doped ZnO thin film are developed, and used as electron transporting layer (ETL) in inverted organic photovoltaics (I-OPVs). Optical and electrical characteristics of ZnO:Cl ETL are investigated depending on the chlorine doping ratio and optimized for high efficient I-OPV. It is found that optimized chlorine doping on ZnO ETL enhances the ability of charge transport by modifying the band edge position and carrier mobility without decreasing the optical transmittance in the visible region, results in improvement of power conversion efficiency of I-OPV. The highest performance of 8.79 % is achieved for I-OPV with ZnO:Cl-x (x=0.5wt%), enhanced ~10% compared to that of ZnO:Cl-x (x=0wt%).

Electrical/Themoelectric characterization of electrodeposited BixSb2-xTe3 thin films

BixSb2-xTe3 films were potentiostatically electrodeposited from acidic nitric baths at room temperature by controlling electrodeposition parameters (i.e. applied potential). Near stoichiometric BixSb2-xTe3 thin films were obtained at applied potentials between −0.10 and −0.15 V versus saturated calomel electrode (SCE). Electrical and thermoelectric property of as-deposited films was degraded with more negative deposition potential, which might be attributed to greater defect density. Post-annealing process in the reducing environment improved electrical and thermoelectric properties possibly due to decrease in antistructure.