Solar cell and method for manufacturing the same

Abstract

A solar cell including a semiconductor layer containing first type impurities and having front and back surfaces, a first portion on the back surface of the semiconductor layer, the first portion being doped with second type impurities, a second portion on the back surface of the semiconductor layer, the second portion being more heavily doped with the first type impurities than the semiconductor layer, a third portion on the back surface of the semiconductor layer, the third portion being doped with the first type impurities more heavily than the semiconductor layer and less heavily than the second portion, a passivation layer on the back surface of the semiconductor layer and contacting the first portion, the second portion and the third portion, and having contact holes corresponding to the first portion and the second portion and an anti-reflection layer formed on the front surface of the semiconductor layer.

What is claimed is: 
     
         1 . A solar cell comprising:
 a semiconductor layer containing first type impurities and having a front surface and a back surface, the front surface being a light incident surface on which light is incident;   a first portion on the back surface of the semiconductor layer, the first portion being doped with second type impurities opposite to the first type impurities, and forming a p-n junction with the semiconductor layer;   a second portion on the back surface of the semiconductor layer, the second portion being more heavily doped with the first type impurities than the semiconductor layer;   a third portion on the back surface of the semiconductor layer, the third portion being doped with the first type impurities more heavily than the semiconductor layer and less heavily than the second portion;   a first electrode on the back surface of the semiconductor layer and connected to the first portion;   a second electrode on the back surface of the semiconductor layer and connected to the second portion;   a passivation layer on the back surface of the semiconductor layer and contacting the first portion, the second portion and the third portion, and having contact holes corresponding to the first portion and the second portion; and   an anti-reflection layer formed on the front surface of the semiconductor layer, and including a silicon nitride layer and a silicon dioxide layer.