This paper presents results of the theoretical analysis and the experimental verification of influence of geometrical parameters of a planar silicon structure emitting the modulated infrared radiation in a wide and continuous spectral range 3-12 μm.The approach is based on the modulation of the thermal emission power of semiconductors in the spectral range of intraband electron transitions. The free-carrier absorption-emission processes are utilized in techniques of dynamic emissivity enhancement. The emitting area was constituted by the base of a p-i-n structure operating well above room temperatures. The signal modulation was realized by the contact injection of free carriers. The changes of current-carrier concentration in the base of p-n diode influence the absorption coefficient (α), therefore also the emissivity (ε), thus allowing for modulation of infrared radiation emitted from the heated structure. Optimization of the structure parameters was aimed at maximal difference between emissivity of this structure heated to about 450K, for cases with and without forward bias applied to the p-n junction. Nearly 1.0 mW output power was achieved at T ~ 450 K with ~0.8 % external power conversion efficiency. The difference of emissivity can be described by: Δε_R = (1-R₁)(R₂η₂+1)(1-η₂)/(1-R₁R₂η₂²)-(1-R₁)(R₂η₁+1)(1-η₁)/(1-R₁R₂η₁²), where η = exp(-α_λd), R - reflection coefficient, α_λ - absorption coefficient at wavelength λ. This equation was applied for calculation of thickness d that enables maximal Δε_R at specific values of R and α. It was shown that high Δε_R for wafers with typical thickness (0.05 cm) requires an application of mirrors with R>0.8. This planar device based on the transparency modulation technique enhanced by the reflecting mirror on the back facet is easy to produce using standard silicon technology. It can be applied for diode matrix used for testing of dynamic characteristics of thermal cameras and generation of infrared imagery.

• Legal notice:
  

  Copyright (c) Pielaszek Research, all rights reserved.
  The above materials, including auxiliary resources, are subject to Publisher's copyright and the Author(s) intellectual rights. Without limiting Author(s) rights under respective Copyright Transfer Agreement, no part of the above documents may be reproduced without the express written permission of Pielaszek Research, the Publisher. Express permission from the Author(s) is required to use the above materials for academic purposes, such as lectures or scientific presentations.
  In every case, proper references including Author(s) name(s) and URL of this webpage: https://science24.com/paper/18162 must be provided.

1. Measurement of distorting magnetic field inside the scanning electron microscope with the use of microscope itself
2. Determination of densities of various dislocation types in GaN – comparison of TEM and improved hot acid etching method
3. TEM study of iridium silicide contact layers for Low Schottky Barrier MOSFETs