Haibo Xiao

Study of microstructure and defects in hydrogenated microcrystalline silicon films

Microcrystalline silicon films were deposited by very high frequency (VHF) plasma-enhanced chemical vapor deposition (PECVD) with different hydrogen dilution. The microstructure of these films was investigated using Raman spectroscopy and infrared absorption (IR) spectra. The crystalline, amorphous, and grain boundary volume fractions Xc, Xa and Xgb were estimated from Raman measurements. An interface structure factor (Rif) is proposed to characterize the grain boundary volume fractions in IR spectroscopy. The density of states (DOS) of the microcrystalline crystalline silicon films were studied by phase-shift analysis of modulated photocurrent (MPC) and photoconductivity spectroscopy. It was observed that DOS increases with increasing grain boundary volume fractions, while the values of electron mobility-lifetime product μeTe decease.

Improvement of microcrystalline silicon N-I-P solar cell by hydrogen plasma treatment for n/i interface

The performance of a nip microcrystalline silicon (μc-Si) solar cell was improved by “alternately deposition and hydrogen plasma treatment method (ADHT)” at n/i interface. The defect densities measured by static capacitance-voltage (C-V) was decreased from 2.37×10¹⁶ cm⁻³ to 1.25 ×10¹⁶ cm⁻³. The short-circuit current Jsc was improved from 14.5 mA/cm² to 17.2 mA/cm² on bared stainless steel substrate and Obtained 24.7 mA/cm² on a.BR substrates.