Summary: | 碩士 === 國立臺北科技大學 === 光電工程系 === 106 === In this study, the conversion efficiency of single-junction GaAs solar cells using (a) double layer (ITO/SiO2) anti-reflection and (b) metal/oxide/semiconductor (MOS) structure deposited by thermally RF-sputter were proposed and demonstrated. Optical reflectance, external quantum efficiency, dark current-voltage, and photovoltaic current-voltage of are measured and compared.
Type-(a): The optical reflectance of double layer anti-reflection was simulated using TFCalcTM optical thin film software to show a low reflective spectrum at the GaAs solar cells. That in the GaAs solar cells with ITO (41 nm) and SiO2 (58 nm) double-layer anti-reflection layer exhibited the best short circuit current density enhancement, its short circuit current density enhancement (ΔJsc) of 28.43% (from 22.19 mA/cm2 to 28.50 mA/cm2) and conversion efficiency enhancement (Δη) of 30.35% (from 18.78% to 24.48%) were obtained.
Type-(b): GaAs solar cells are fabricated using metal-oxide/semiconductor (MOS) structures using Al2O3 or TiO2 as a oxide films, Applying various voltages on the ITO electrode to enhance photovoltaic performance was observed, For the a case of MOS-structure cell, Al2O3/ITO, the short-circuit current density enhancement (ΔJsc) of 15.25% (from 22.69 mA/cm2 to 26.15 mA/cm2) and conversion efficiency enhancement (Δη) of 13.35% (from 18.28% to 20.72%) were obtained; and the oxide layer was TiO2 sputtered ITO transparent electrode (TiO2/ITO), the short-circuit current density enhancement (ΔJsc) of 21.09%(from 23.14 mA/cm2 to 28.02 mA/cm2) and conversion efficiency enhancement (Δη) of 22.40% (from 18.75% to 22.95%) were obtained. To study the biase effection MOS GaAs solar cell, the cell biased at -3.6 V, Jsc of 34.43 mA/cm2, and η of 26.50% foe the cell with Al2O3/ITO were obtained. Similarly, the cell with TiO2/ITO and biased at -3.6 V, Jsc of 36.64 mA/cm2 and η of 28.07% were obtained.
|