Solid State Physics Laboratory

About: Solid State Physics Laboratory is a facility organization based out in Delhi, India. It is known for research contribution in the topics: Quantum dot & Dielectric. The organization has 1754 authors who have published 2597 publications receiving 50601 citations.

Dislocation density investigation on MOCVD-grown GaN epitaxial layers using wet and dry defect selective etching

Abstract: Results on the investigations of the dislocation etch pits in the GaN layers grown on sapphire substrate by metal organic chemical vapor deposition are revealed by wet chemical etching, and dry etching techniques are reported. The wet etching was carried out in molten KOH, and inductively coupled plasma (ICP) was used for dry etching. We show that ICP using dry etching and wet chemical etching using KOH solution under optimal conditions give values of dislocation density comparable to the one obtained from the high-resolution X-ray diffraction, atomic force microscopy and transmission electron microscopy investigations. Investigated threading dislocation density is in the order of ~109/cm2 using different techniques.

Imaging the lateral shift of a quantum point contact using scanning gate microscopy

Abstract: We perform scanning-gate microscopy on a quantum-point contact. It is defined in a high-mobility two-dimensional electron gas of an AlGaAs/GaAs heterostructure, giving rise to a weak disorder potential. The lever arm of the scanning tip is significantly smaller than that of the split gates defining the conducting channel of the quantum-point contact. We are able to observe that the conducting channel is shifted in real space when asymmetric gate voltages are applied. The observed shifts are consistent with transport data and numerical estimations.