眞性少數擔體의 壽命이 실리콘 太陽電池의 起電力에 미치는 影響

The Influence of the Intrinsic Minoriy Carrier Lifetime to the Photovoltage of Silicon Solar Call

실리콘 太陽電池를 하나의 다이오드로 보고 빛을 遮斷시킨 狀態에서 다이오드의 順方向 l-v 特性曲線을 관찰해 보면 이 特性曲線에서는 少數擔體에 起因된 平坦部分이 나타나게 된다. 그러나 실리콘 太陽電池에 빛을 熙射시키면 이 電池내에 발생된 眞性少數擔體들의 이동방향이 少數擔體와 反對方向이 되어 順方向 特性曲線의 平坦部分이 消滅되는 현상이 나타난다. 이 消滅되는 平坦部分의 길이는 실리콘 太陽電池內의 結晶欠陷에 의한 眞性少數擔體들의 平均壽命에 관계되며, 太陽電池의 起電力을 支配하는 要因이 되고 있다. 本 硏究에사 測定된 실리콘 太陽電池 試料 (A), (B)및 (C)에서 消滅된 平坦部分의 길이는 각각 1.0㎝, 0.6㎝ 및 0.3㎝이었고, 起電力은 0.54 V, 0.44 V 및 0.41V이었다.

Observing the forward I-V characteristic of a silicon solar cell which is regarded as a diOde under unirradiated condition, a flat part which is caused by the minority carriers can be seen on the characteristic. Under irradiated condition of the cell, however the flat part of the characteristic can be died away mostly in terms of the intrinsic minority carriers. The cancelled length in the flat part is keenly related to the average lifetime at the intrinsic minority carriers which are caused by the crystal defects in the cell, so that it has been turned out that the canceled length should be responsible for the average lifetime of the intrinsic minority carriers as well as the magnitude of the photovoltage of the cell. According to the measured results in this research, the cancelled length in each silicon solar cell sample (A),(B) and (C) was 1.0cm, 0.6cm, 0.3cm and the corresponding photovoltage of each cell was 0.54V, 0.44V and 0.41V respectvely.