Fabrication and Characterization of a-Si and Heterojuncion of Si thin film Solar cell by Chemical Vapor Deposition (CVD)

以化學氣相沉積系統製備非晶矽以及異質接面矽薄膜式太陽能電池之特性

張弘諭(Hung-Yu Chang)

指導教授 ： 黃惠良

國立清華大學/電機資訊學院/電子工程研究所/碩士(2010年)

摘要

In this work, mainly depart two parts, one is to fabricate p-i-n and p-n-n amorphous silicon thin film solar cell by HDPCVD system, the other one is to fabricate quasi-SPA thin film solar cell by HDPCVD system and ECRCVD system.
First we deposited the films on wafer which deposited oxide and Al layer. And start to fabricate a-Si p-i-n and p-n-n solar cells and checking the property of diode. It was found that both of these two structures (p-i-n and p-n-n) show almost the same efficiency. However, p-n-n cell shows higher Jsc and lower Voc than that of p-i-n cell. This is attributed to the influence of insufficiently heavy-doped a-p layer that results non-ideal ohmic contact with metal and, therefore, weaker drift field cross absorb
layer. The parallel resistance is insufficiently high, leading to leakage through the cells. In the other hand, the deposition rate of n-type Si layer was too higher to form the high quality n-type as compared with the i-type layer.
In second part, the quasi-SPA solar cells were fabricated. It is observed that quasi-SPA solar cell with ECRCVD deposited p-layer exhibits higher efficiency than that with HDPCVD deposited p-layer. This is due to the
higher doping concentration of p layer. However, the F.F. of quasi-SPA solar cell with HDPCVD deposited p-layer is higher since there is a native oxide formed which higher series resistance causes on the sample surface during transportation from HDPCVD to ECRCVD system.

關鍵字

非晶矽 ； 太陽電池 ； 異質接面

並列摘要

全篇主要分為兩部分做探討，第一部分為使用 HDPCVD 製作非晶矽
p-i-n 結構和 p-n-n 結構太陽電池，第二部分則是使用 HDPCVD 和
ECRCVD 製作類-SPA 結構矽太陽電池。
首先，我們在晶圓上沉積氧化層及鋁金屬，接著製作非晶矽 p-i-n 薄膜和 p-n-n 薄膜，並且量測其相關特性，我們可以發現兩種結構幾乎呈現相同的效率，但是 p-n-n 結構有著較高的短路電流以及較低的開路電壓。其中 p 層載子濃度不夠高導致無法形成較理想的歐姆接觸，並且造成空閥區電場無法落在吸收層上。另一方面，吸收層 n 層沉積速率遠高於 i層，導致 n層薄膜品質不如 i層，造成較低的開路電壓。
第二部分，當我們在製作類-SPA 結構時，可以發現使用 ECRCVD 沉積較高載子濃度的 p 層確實可以提升電池的效率，但是也由於在機台轉移的過程中形成氧化層造成較高的串聯電阻導致填充因子的下降。

並列關鍵字

a-Si ； solar cell ； heterojunction

參考文獻

Pallab Bhattacharya, “Semiconductor Optoelectronic devices” Second edition, P.158, Pearson Education Taiwan Ltd. (2005).

Peter Wurfel, “Physics of Solar Cells”, WiLEY-VCH (2005).

James D. Plummer, Michael D. Deal, and Peter B. Griffin, Silicon VLSI Technology, Chapter 9, (2000).

陳學龍，王水進“IZO透明金屬薄膜之研製及其在GaN基LEDs之應用研究”，國立成功大學/微電子工程研究所2002。

Effective repair to ultra-low-k dielectric material .kÈ2.0. by hexamethyldisilazane treatment