2018年6月25日星期一

Ge/Si Heterojunction Photodiodes Fabricated by Low Temperature Wafer Bonding

Ge/Si heterojunctions are formed by wet wafer bonding at annealing temperatures of 250 or 350 °C. Photodiodes fabricated using Ge/Si heterojunctions exhibit photocurrents flowing over the heterojunction with an internal quantum efficiency higher than 80% at wavelengths between 1000 and 1550 nm. The measured photocurrent–voltage and capacitance–voltage characteristics reveal that the electrical property of the heterojunctions is the same as that for samples fabricated by higher temperature annealing

Source:IOPscience

For more information, please visit our website: www.semiconductorwafers.net,

2018年6月4日星期一

Ultralarge transient optical gain from tensile-strained, n-doped germanium on silicon by spin-on dopant diffusion

The direct band gap optical gain of tensile-strained, highly n-doped germanium on silicon is investigated by femtosecond ultrafast transmittance spectroscopy. A germanium film with 0.22% tensile strain is grown on a silicon substrate by using molecular beam epitaxy. An activated doping concentration up to 4 × 1019 cm−3 is achieved by phosphorus diffusion from a spin-on dopant source. The transmittance of the germanium film is clearly increased upon increasing the pump power. A peak optical gain of up to 5300 cm−1 around 1.7 µm and a gain spectrum broader than 300 nm are obtained. These results show a simple yet promising way to realize gain medium for monolithic-integrated germanium lasers.


Source:IOPscience

For more information, please visit our website: www.semiconductorwafers.net,