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 2H 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 2O) 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 2O and B 2H 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 2O and B 2H 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 2H 6 ratios of 0.5 and 1% respectively. © 2012 KIEEME. All rights reserved.