Coordination defects in amorphous silicon and hydrogenated amorphous silicon: a characterization from first-principles calculations

First-principles study of hydrogenated amorphous silicon

K. Jarolimek,1,2 R. A. de Groot,2 G. A. de Wijs,2 and M. Zeman1 1DIMES, Delft University of Technology, Feldmannweg 17, 2600 GB Delft, The Netherlands 2Electronic Structure of Materials, Institute for Molecules and Materials, Faculty of Science, Radboud University Nijmegen, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands Received 23 May 2008; revised manuscript received 9 February 2009; p...

Atomistic models of hydrogenated amorphous silicon nitride from first principles

We present a theoretical study of hydrogenated amorphous silicon nitride a-SiNx :H , with equal concentrations of Si and N atoms x=1 , for two considerably different densities 2.0 and 3.0 g /cm3 . Densities and hydrogen concentration were chosen according to experimental data. Using first-principles molecular-dynamics within density-functional theory the models were generated by cooling from th...

Light-induced Defects in Thermal Annealed Hydrogenated Amorphous Silicon

The metastable defects of a-Si:H samples annealed at temperatures in the 300-550°C range have been studied by photothermal deflection spectroscopy (PDS). The light-soaked samples show an increase in optical absorption in the 0.8 to 1.5 eV range. The metastable defect density decreases when the annealing temperature increases, while the defect density increases. This decrease in the metastable d...

Defects in Amorphous Semiconductors: Amorphous Silicon

Defects in disordered (amorphous) semiconductors are discussed, with an emphasis on hydrogenated amorphous silicon. The general differences between defect phenomena in crystalline and amorphous hosts are described, and the special importance of the electron–phonon coupling is stressed. Detailed calculations for amorphous Si are presented using accurate first principles (density-functional) tech...

Luminescence quenching in erbiumdoped hydrogenated amorphous silicon