利用氫氣回火鈍化對矽晶太陽能電池效率提升的研究

Abstract

本論文主要目的是研究氫氣鈍化對多晶矽太陽能電池轉換效率的影響，將網版印刷後的多晶矽太陽能電池成品通入於氫氣爐管中，比較實驗前後的太陽能電池電性特性，觀察轉換效率改善情形。 首先在不同的氫氣爐管溫度條件下，通氫氣於多晶矽太陽能電池，發現在350°C溫度條件下，太陽能電池轉換效率有最佳的改善。接著在350°C溫度條件下，通氫氣於各種不同效率的多晶矽太陽能電池，發現氫氣鈍化可以改善太陽能電池的串聯電阻與填充係數，進而提升太陽能電池的轉換效率。 最後在350°C溫度條件下，通氫氣於不同串聯電阻的多晶矽太陽能電池，實驗結果發現太陽能電池串聯電阻越大，則轉換效率提升的幅度越大，轉換效率最高可以提升約0.95%。主要原因是因為氫氣會影響正銀與矽半導體之間的電流移動，減少玻璃層的金屬氧化物，增加電流穿隧機率，造成串聯電阻減少和填充係數增加，因此提升太陽能電池的轉換效率。

The main purpose of this thesis is to study the influence of hydrogen passivation on silicon solar cell conversion efficiency by applying hydrogen plasma to silicon solar cells with different efficiency and under different temperature condition. Improvements of both the electrical characteristics and efficiency of silicon solar cells are observed after the hydrogen passivation process. Our experimental results show the highest conversion efficiency improvement of the silicon solar cell is raised by 0.95%. The influence of the hydrogen passivation on the conversion efficiency is close related to the reduction of silicon solar cell series resistance. It is because that the hydrogen affects the current path from the Ag crystals into the bulk of the Ag finger, reducing the metal oxides in the glass layer and increasing current tunneling probability in the Si. Therefore, it decreases overall resistivity of silicon solar cell devices under test and leads to the increase of the conversion efficiency.