Porous silicon optical devices and Si/SiO2 quantum wells: recent results

摘要

The recent progress accomplished in our research group is here presented. Firstly porous Si (PS) microcavities were formed on p(-)-type-doped (6-9 Ohm cm) substrates with very narrow bandwidth (6 nm) and a good ratio of the peak to background emission: reaching at the same time a high emission quantum efficiency. Secondly light-emitting diodes (LEDs) based on n-type-doped Si/PS heterojunctions were studied. The improvement in the proposed LED structure with respect to the usual metal/PS LED is demonstrated. Anodic oxidation experiments show further improvements in the LED efficiency. Thirdly, SiO2/Si/SiO2 quantum wells with room-temperature efficient light emission in the visible range were investigated. We report here the preparation and photoluminescence properties of thin SiO2/Si layers obtained by low-pressure chemical vapour-phase deposition and thermal oxidation processes. The growth technique is fully compatible with standard very-large-scale integration complementary metal-oxide-semiconductor technology. [References: 14]