Effect of Surface States on Piezoelectric Photothermal Specta of Silicon Single Crystals

Abstract

The effect of surface states on the piezoelectric photothermal (PPT) spectra of p- and n-type, <100> oriented, single crystal silicon was investigated. We showed that a PPT signal bearing a lower energy edge around 1.04 eV at room temperature was due to the bulk effect. This bulk signal was greatly affected by another signal bearing a broad peak around 1.18±0.01 eV. The broad peaked signal was found to be due to the surface states. The variation in amplitude and phase of the 1.18±0.01 eV signal revealed that the surface states were affected by the ambient illumination and low-temperature thermal annealing at 350 K. The results also indicated that a very low absorption coefficient in indirect semiconductors can be effectively observed by using the proposed PPTS technique.

Band gap energy fluctuations in InGaN films grown by RF‐MBE with changing nitrogen supply rate investigated by a piezoelectric photothermal spectroscopy

“…PPTS technique is effective method to obtain information concerning non-radiative electron transitions. Our group has succeeded in studying non-radiative recombination process of many semiconductors regardless of the forms of bulk, thin film and quantum well structure [7][8][9][10]. This may lead to understand how to improve the efficiency of the optoelectronic devices.…”