- 學位論文
磷化銦系-太陽能電池以不同窗口層厚度與電極圖形之最佳化
Optimized Window Layer and Finger Pattern for InP-based Solar Cell
摘要
本研究探討的主題是藉由改變不同厚度磷化銦窗口層，以及使用不同電極圖形，來獲得高效率的太陽能電池。首先，研究Au/Ni/Au/Ge/N為N型磷化銦以及Au/Cr/AuBe為P型磷化銦的金屬-半導體接觸，藉由傳輸線的方法，我們獲得N型磷化銦及P型磷化銦之特性接觸電阻9.85x10-7Ωּcm2 和2.24x10-5 Ωּcm2。 然後，以標準的黃光製程、金屬蒸鍍、拆除技術、抗反射層、快速退火及蝕刻等技術，來製做磷化銦系太陽能電池。每一個太陽能電池面積為 0.16平方公分，設計的光罩遮蔽率為10~15%。研製出來的太陽能電池的短路電流密度為43.1mA，開路電壓為0.38 V，填充因子為0.54，效率約為10% (AM1.5，25 ℃)。 最後，我們從量測得到之太陽能電池之電流-電壓關係來計算串聯電阻與並聯電阻。藉由短路電流與光強度的曲線圖，來獲得串聯電阻。在低照度的光強下，以開路電壓和短路電流的曲線圖來獲得並聯電阻。由實驗結果，顯示不同的窗口層厚度的太陽能電池，較薄之磷化銦窗口層獲得效率較高，以及使用不同的電極圖形，可獲得不同的效率，取二者之最佳效率，為此研究主題之最佳化。
並列摘要
In this article, we developed and characterized the high efficiency InP-based solar cells. Firstly, low ohmic contact resistance of various metal combinations, deposited by E-beam evaporation on InP, were studied. The metallization of Au/Ni/Au/Ge/Ni on n-InP and Au/Cr/AuBe on p-InP exhibit specific contact resistances as low as 9.85x10-7 Ωּcm2 and 2.24x10-5 Ωּcm2, respectively. Then, the front grid was defined by standard photolithography and lift-off techniques. The cell area of 0.16 cm2 was defined and isolated from adjacent cells by mesa etching. Front grid shadowing was 10~15% of the area of the solar cells. The device parameters of InP-based solar cells were Jsc=43.1 mA/cm2, Voc=0.38 V, FF=0.54, η=10% (AM1.5, 25 ℃). Finally, we determined the series resistance and the shunt resistance from I-V plots. One method is proposed which uses the observed nonlinearity in the short-circuit current versus light curve to determine the series resistance of solar cell. The shunt resistance is determined from measurements of open-circuit voltage and short-circuit current at very low illumination conditions under which a linear relationship exists such that Voc=RshIsc. (1) The conversion efficiency change significant (6~10%) with the decreasing in window layer thickness to 0.25μm. (2) The higher conversion efficiency obtained by pattern-4. By the description of the above two, these are the optimization of this research.