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.

The influence of As and Ga prelayers on the metal-organic chemical vapor deposition of GaAs/Ge

Abstract: GaAs epilayers were grown on Ge by metal-organic chemical vapor deposition (MOCVD) with As or Ga prelayers. The grown epilayers were examined for surface morphology, antiphase domain (APD) presence, and optical quality using optical interference contrast microscopy, molten potassium hydroxide (KOH) etching, and photoluminescence (PL) spectroscopy. The As prelayer results in smooth, shiny, and APD-free epilayers with good optical quality. In contrast, the Ga prelayer results in a rough surface with APDs and higher carbon incorporation.

Optimization of π – Gate AlGaN/AlN/GaN HEMTs for Low Noise and High Gain Applications

Abstract: This paper presents a comprehensive TCAD based assessment to evaluate the intrinsic gain and minimum noise figure metrics of the T – Gate, and the π – Gate AlGaN/AlN/GaN HEMTs along with their recessed architectures. The work presented in this paper, to the best of author’s knowledge, is first in its attempt to systematically bring out both the effect of minimum noise figure metrics and intrinsic gain at the device level for the π – Gate architecture and their recessed counterparts whilst evaluating its stability for high frequency operations. Comparison demonstrates an enhancement in intrinsic gain by 64.5% in case of asymmetric π – Gate and 77% for asymmetric recessed π – Gate in comparison to their T – Gate counterparts. Further, the said architectures possess a wider range of flat gain operation with suppressed values of minimum noise figure metrics. These modifications result in a modest trade off in the minimum noise figures when best case is considered and compared with their T – Gate counterparts. Additionally, it is also demonstrated that such device architectures demonstrate much stable high frequency operation in comparison to their primer. The results so presented establish the superiority of the π – Gate AlGaN/AlN/GaN HEMTs for low noise and high gain applications.

Etching of Mesa Structures in HgCdTe

Abstract: Mesa structures were etched in HgCdTe using different Br2/HBr/Ethylene glycol (EG) formulations. Etch rate and degree of anisotropy (A) were studied in detail for all of the combinations. Addition of EG to the conventional etchant gave A>0.5, with controllable etch rates. Optimum etchant composition was determined to be 2% Br2 in a 3:1 mixture of EG:HBr. This composition resulted in a good anisotropy factor of ∼0.6 and a reasonably optimum etch rate of ∼2.5 µm/min, with rms surface roughness of ∼2 nm. Kinetics of the etching reaction have also been studied for the optimum etchant concentration and an etching mechanism has been proposed.