Effect of Oxygen and Diborane Gas Ratio on P-type Amorphous Silicon Oxide films and Its Application to Amorphous Silicon Solar Cells

Abstract

We reported diborane (B 2 H 6 ) doped wide bandgap hydrogenated amorphous silicon oxide (p-type a-SiOx:H) films prepared by using silane (SiH 4 ) hydrogen (H 2 ) and nitrous oxide (N 2 O) in a radio frequency (RF) plasma enhanced chemical vapor deposition (PECVD) system. We improved the E opt and conductivity of p-type a-SiOx:H films with various N 2 O and B 2 H 6 ratios and applied those films in regards to the a-Si thin film solar cells. For the single layer p-type a-SiOx:H films, we achieved an optical band gap energy (E opt ) of 1.91 and 1.99 eV, electrical conductivity of approximately 10 -7 S/cm and activation energy (E a ) of 0.57 to 0.52 eV with various N 2 O and B 2 H 6 ratios. We applied those films for the a-Si thin film solar cell and the current-voltage characteristics are as given as: V oc = 853 and 842 mV, J sc = 13.87 and 15.13 mA/cm 2 . FF = 0.645 and 0.656 and η = 7.54 and 8.36% with B 2 H 6 ratios of 0.5 and 1%respectively.