A new type of IR luminescence

Multifunctional controlled IR-emitting unit

“…Here E g is the energy of the semiconductor forbidden gap. In the first case positive (PL) and negative (NL) luminescence [5][6][7] were investigated, while in the second case thermal emission (TE) of the nonequilibrium charge carriers was studied [8][9][10]. The unit base thickness d = 3.9 mm was comparable to L d .…”

Un-cooled infrared (8–12 μm) emitters of positive and negative contrast

“…In the ideal case (R 2 ¼ 1 and R 1 ¼ 0--see curve 1) DR may increase, in the enhancement mode, from 0 up to 1, if the semiconductor was initially transparent (u 0 ¼ 1). If R 2 < 1, then DR decreases at any R 1 value (see curves [2][3][4]. An increase of the reflection coefficient at the front face also results in a decrease of DR value (see curve 5).…”

“…In other words, we assume that a heated semitransparent semiconductor is completely enclosed on all sides by a background radiation whose temperature is below that of the semiconductor. Such a physical model was used when studying TR [3,4]; and just that same model lays the groundwork for the principles of radiation source operation [2]. There exists, however, another possibility to modulate TR from a structure made up of a semiconductor layer (whose transparency can be controlled by external actions) and a non-transparent ''hot'' substrate.…”

“…This causes the appearance of TR modulation at a constant value of crystal lattice temperature. In this case one can obtain radiation power increase (at charge carrier injection [3]) or decrease (at charge carrier exclusion [4]). …”

Negative luminescence of InAs/GaSb superlattice photodiodes

“…Pioneering work on this phenomenon was performed by V.I. Ivanov-Omskii et al, and Malyutenko et al demonstrating NL [1,2] in the InSb and HgCdTe material systems. Other groups have also documented the numerous potential applications [3,4] of NL devices, which include dynamic cold shields for focal plane arrays and infrared scene simulators.…”