Narrow-bandgap semiconductors

The synthesis and characterization of narrow-bandgap semiconductors, especially SnS2 and SnS, have received much attention in the last few years, due to their optical and electronic properties. xin sulfides comprise an interesting class of semiconductor materials. A variety of phases are known, such as SnS (herzenbergite), SnS2 (berndtite - 70 polytypes known), Sni+ Sn (non-stoichiometric),... 

In this paper, we report on the development of InN as a potential narrow bandgap semiconductor source of THz radiation nnder 1550 nm fs or CW laser excitation The... 

D.R. Lovett, Semimetals Narrow-Bandgap Semiconductors, Pion, London, p.l82, 1977. 

In all cases the metal ion was monovalent and the compounds contain no Q-Q bonds. In most cases the compounds are valence precise, diamagnetic, narrow bandgap semiconductors or semimetals. 

In this chapter, we first divide NIR NMs into five species carbon-based materials, quantum dots (QDs), noble metal-based nanoparticles (NPs), upconversion nanoparticles (UCNPs), and narrow-bandgap semiconductors. Then, we focus primarily on the progress of their toxicity studies in the past several years, discuss in detail how the biophysicochemical properties of NIR NMs influence their in vitro and in vivo toxicity, present a broad overview of the available in vitro and in vivo toxicity assessments of NIR NMs, and finally frame the future outlook for NIR NMs by highlighting areas of exceptional promise and challenges. Our emphasis here is mainly on discussion that could offer future opportunities to design and create NIR NMs with good biocompatibility as well as excellent functionalities, rather than attempting to provide a complete historical survey. 

Recombination Mechanisms in Direct Narrow-Bandgap Semiconductor... 

The further text shortly considers all of the three main bulk generation-recombination mechanisms in direct narrow-bandgap semiconductors. A unilied g-r term is presented to be utilized in modeling and optimization of photonic IR detectors. In addition to that, some useful approximations are given that may significantly speed up and simplify modeling. 

Hall s expression for spontaneous radiative recombination rate, obtained using Bardeen s approximation for the absorption coefficient of narrow-bandgap semiconductors a [E—EgY [18] is often used to calculate the generation rate G,o [19, 20]. A generalization of Hall s expression is given as [29, 351]... 

Hall s expression is often used even for narrow-bandgap semiconductors with nonparabobc bands and with an arbitrary degeneration [19, 21, 22]. Most of the calculations in this work were performed using the accurate model of absorption coefficient, based on Kane s model with taking into account the Urbach band tailing [23]. For some calculations an empirical approximation for HgCdTe absorption coefficient was used [24]... 

An important consequence of the use of nonequUibrium methods is that they enable the operation of bipolar and unipolar devices in narrow-bandgap semiconductors at elevated temperamres and offer the possibility to use doping level adjustment to control their performance. This is called pseudo-extrinsic behavior. 

Table 3.1 Some transp

This is simultaneously a form of the current density for the case of negligible magnetic field. We conclude that the influence of magnetic field to a narrow-bandgap semiconductor can be represented by introducing new, magnetic field-dependent anisotropic (tensorial) drift mobilities and diffusion coefficients. 

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