The growth and luminescence of SiGe dots

It is found that the SiGe alloy self-organizes into uniform quantum dots embedded in the Si layer during the growth of a strained SiGe/Si superlattices on a Si(0 0 1) substrate by molecular beam epitaxy. The energy of photoluminescence from the quantum dots is higher than that of the indirect band gap of Si, and the luminescence intensity of the quantum dots exceeds that of a quantum well by three orders of magnitude.