Figure 1
From: Giant electro-optic effect in Ge/SiGe coupled quantum wells

(a) Cross section of the sample showing the Ge/SiGe CQW between n-doped SiGe and p-doped SiGe to form a PIN diode. The stack is grown on a Si substrate via a graded buffer by LEPECVD. (b) X-ray diffraction: the agreement between experimental and simulated ω-2θ scans around the(004) reflection confirms that the CQW structure has been realized. (c) Current density of the device as a function of the applied voltage.