Effects of Anodization Temperature on Photoluminescence from Porous Silicon

Abstract

The effects of anodization temperature on the photoluminescence (PL) spectrum of porous silicon (Si) have been studied. The luminescence intensity increases exponentially and the peak wavelength decreases monotonically with increasing anodization temperature during formation of pores on Si. The PL intensity increases with decreasing the measurement temperature and reaches the maximum at about 200 K. With a further decrease of the measurement temperature, however, the intensity decreases. The increase rate of the PL intensity with decreasing temperature is found to be much faster for the samples anodized at lower temperatures. Using electron spin resonance the defects of the samples anodized at lower temperatures such as 0 and 10°C are identified to be amorphous centers (a‐centers), while those of the samples anodized at higher temperatures such as 30 and 40°C are attributed to Si dangling bonds.