Optical and Electrical Properties of Nanocrystalline Films Formed from Amorphous Silicon by Thermal Annealing and Stain Etching

Nanocrystalline films were prepared from amorphous silicon (a-Si) by using rapid thermal annealing (RTA) and stain etching (SE). The volume fraction and mean diameter of silicon nanocrystals (nc-Si) in the prepared films were determined by means of the Raman spectroscopy. The optical reflection data were analyzed by using an effective medium approximation (Bruggeman model), which allowed us to estimate the film porosity. The specific electrical resistivity and photoluminescence (PL) were found to depend strongly and in an opposite way on the preparation conditions. The most efficient PL in the spectral range from 600 to 1000 nm was detected for the films, which were annealed and stain-etched subsequently.