In this thesis, InP based solar cells using double hetero structure were fabricated and their performances were characterized. And single layer anti-reflection coating with silicon nitride and silicon monoxide was designed and fabricated.
Double hetero-junction p(InP)-i(InGaAs)-n(InP) solar cell suitable for bottom cell of tandem solar cell has higher open circuit voltage compared to conventional InGaAs $n^{+}p$, $p^{+}n$, or p-i-n homo-junction structure solar cells. InP/InGaAs double hetero-junction solar cell was fabricated. Its open-circuit voltage is 0.4V (the highest ever reported) and efficiency is 10.05 %.
Double hetero-junction p(InP)-i(InGaAsP)-n(InP) solar cell can have higher efficiency than conventional InP homo-junction solar cell. According to our model, if bandgap of InGaAsP is higher than 1.05eV, InP/InGaAsP double hetero-junction solar cell has higher efficiency of 1.4% than InP homo-junction solar cell at InGaAsP bandgap of 1.18eV, maximally. Double hetero-junction p(InP)-i(InGaAsP, $ E_g=1.1eV$)-n(InP) solar cell and InP homo-junction solar cell were fabricated. Their efficiency is 12.45% and 8.29%, respectively. InP/InGaAsP double hetero-junction solar cell has higher efficiency of 4.16% than InP homo-junction solar cell. Efficiency improvement owing to double hetero-junction structure is 0.8% of 4.16%.
Because of single layer AR coating with silicon nitride, and silicon monoxide, efficiency of cell was enhanced 0.5%, 2.86%, respectively. Therefore silicon monoxide is more suitable for single layer AR coating than silicon nitride
