Seungil Park

Enhanced photocurrent of Si solar cell with the inclusion of a transparent indium tin oxide thin film

We investigated the enhanced photocurrents in crystalline Si solar cells with the inclusion of indium tin oxide thin film. The indium tin oxide enhances the quantum efficiency and reduces photoreflectance in the spectral region of 310–1048 nm. The enhanced photocurrent is ranged at the Si band edge for the spectral peak near 1033 nm. For the subband gap region, the photocurrent is strongly reduced by the indium tin oxide thin film, indicating that the transmission of infrared spectra was prevented by plasmonic metamaterial effect. The fabricated cell showed the short circuit current density enhanced due to the carrier excitation behavior at conduction band of the infrared spectra induced metallic indium tin oxide thin film. The enhanced shunt resistance of the pn junction is related to the blocking of Ag paste penetration into the Si emitter layer by the indium tin oxide thin film during fabrication process.

Enhanced quantum efficiency of amorphous silicon thin film solar cells with the inclusion of a rear-reflector thin film

We investigated the growth mechanism of amorphous silicon thin films by implementing hot-wire chemical vapor deposition and fabricated thin film solar cell devices. The fabricated cells showed efficiencies of 7.5 and 8.6% for the samples without and with the rear-reflector decomposed by sputtering, respectively. The rear-reflector enhances the quantum efficiency in the infrared spectral region from 550 to 750 nm. The more stable quantum efficiency of the sample with the inclusion of a rear-reflector than the sample without the rear-reflector due to the bias effect is related to the enhancement of the short circuit current.

Enhancement effect of short-circuit currents of Si solar cells with inclusion of indium tin oxide layers on metal–semiconductor interfaces

We investigated the enhancement effect on short-circuit currents by indium tin oxide contact layers imbedded in metal–semiconductor interfaces in Si solar cells. Both samples that incorporate the thin film layer and the crossed finger lines of indium tin oxide exhibit an enhancement of p–n junction photocurrents and depletion capacitances with enhanced bulk donor concentrations at the emitter contacts. The indium tin oxide layer provides the passivation layer on the Si emitter surface with reduced trap states and the carrier transport layer for charge collection. The Si solar cells with indium tin oxide showed improved performance in shunt resistance and short-circuit current.