In this article, we present an overview of a focal plane array (FPA) with 640 × 512 pixels based on the AlGaAs quantum well infrared photodetector (QWIP). The physical principles of the QWIP operation and their parameters for the spectral range of 8–10 μm have been discussed. The technology of the manufacturing FPA based on the QWIP structures with the pixels 384 × 288 and 640 × 512 has been demonstrated. The parameters of the manufactured 640 × 512 FPA with a step of 20 μm have been given. At the operating temperature of 72 K, the temperature resolution of QWIP focal plane arrays is less than 35 mK. The number of defective elements in the matrix does not exceed 0.5%. The stability and uniformity of the FPA have been demonstrated.
Part of the book: Two-dimensional Materials for Photodetector
A systematic study of kinetics and thermodynamics of Si (111) surface nitridation under ammonia exposure is presented. The appeared silicon nitride (8 × 8) structure is found to be a metastable phase. Experimental evidences of graphene-like nature of the silicon nitride (8 × 8) structure are presented. Interlayer spacings in the (SiN)2(AlN)4 structure on the Si (111) surface are found equal to 3.3 Å in SiN and 2.86 Å in AlN. These interlayer spacings correspond to weak van der Waals interaction between layers. In contrast to the widely accepted model of a surface structure (8 × 8) as monolayer of β-Si3N4 on Si (111) surface, we propose a new graphene-like Si3N4 (g-Si3N3 and/or g-Si3N4) model for the (8 × 8) structure. It is revealed that the deposition of Al atoms on top of a highly ordered (8 × 8) structure results in graphene-like AlN (g-AlN) layers formation. The g-AlN lattice constant of 3.08 Å is found in a good agreement with the ab initio calculations. A transformation of the g-AlN to the bulk-like wurtzite AlN is analyzed.
Part of the book: 2D Materials