使用Ag金屬粒子輔助式蝕刻技術製作具有微米孔洞結構砷化鎵 混合型光伏元件之研究

An investigation on hybrid photovoltaic device of microporous GaAs by Ag metal-assisted etching technique

周育正(Yu-Cheng Chou)

指導教授 ： 陳隆建

國立臺北科技大學/電資學院/光電工程系研究所/碩士(2010年)

https://doi.org/10.6841/NTUT.2010.00164

摘要

本論文利用金屬輔助式蝕刻技術在無通電下製作出具有微米等級的孔洞於n型砷化鎵(GaAs)基板，觀察其不同時蝕刻時間條件下砷化鎵基板表面型態與反射光譜，並利用摻雜碘(I2)的鋅酞花菁(ZnPc)作為p型有機半導體與n型砷化鎵形成混合型的p-n接面，再以銦錫氧化物(Indium Tin Oxide，ITO)作為上部電極，完成微米孔洞結構砷化鎵混合型光伏元件。
實驗結果顯示隨著蝕刻時間的增長孔洞形成的結構開始明顯、孔洞密度大幅提升，孔洞的深度也開始出現，與有機材料接觸面積更加提升，並在蝕刻時間20分鐘有較低的反射率，得到元件轉換效率2.14%(AM1.5,10mW/cm2)；此外，對於砷化鎵基板表面氧化層的蝕刻，於蝕刻90s時短路電流密度從2.24 mA/cm2提升至2.91 mA/cm2，其原因為氧化層可能阻擋有機材料與砷化鎵接觸界面，使激子產生後載子不易傳輸出來，適當的蝕刻也使串聯電阻下降，轉換效率上升至3.3%，最後摻雜金奈米粒子(Gold Nano-particle, GNP)，加了金奈米粒子做為緩衝層後，減少電子電洞複合提高短路電流，短路電流再次增加，得到最佳轉換效率3.64%。

關鍵字

砷化鎵 ； 金屬輔助蝕刻 ； 鋅酞花菁 ； 混合型太陽電池

並列摘要

This work reports on the photovoltaic properties of zinc phthalocyanine (ZnPc) films with I2 dopant, and sandwiched between indium tin oxide (ITO) and n-type microporous GaAs substrates. The microporous morphology on GaAs substrates were fabricated utilizing Ag metal-assisted etching technique under electroless condition. Then, we investigates the surface morphology of microporous GaAs substrates with different etching times.
The experimental results indicated the microporous structures of GaAs are larger and clearly defined as increasing etching time. The lower reflectivity of microporous structures was observed in 20 min of etching time. As increasing the etching depth and porous density, the interfacial area between ZnPc and porous GaAs also increases; and the solar energy-to-electricity conversion efficiency of photovoltaic device obtain about 2.14% under AM 1.5, 10 mW/cm2. Furthermore, the porous GaAs substrate immersed in BOE (Buffer oxide etch) in 90s to remove GaAs native oxide, the short-circuit density Jsc is raising from 2.24 to 2.91 mA/cm2 . Also the oxide layer could work as a barrier to reduce the electron transfer at the ZnPc/ porous GaAs interface. In addition to add golden nanoparticle layer between ZnPc and porous GaAs can promote short-circuit current density Jsc. Eventually, the best photovoltaic properties were obtained about Jsc = 3.38 mA/cm2, Voc = 0.57 V and η =3.64 %.

並列關鍵字

Gallium Arsenide (GaAs) ； Metal-assisted etching technique ； Zinc Phthalocyanine (ZnPc) ； Hybrid solar cell

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