Electroluminescence and lasing properties of highly Bi-doped PbTe epitaxial layers grown by temperature difference method under controlled vapor pressure

Mid-infrared photoconductive properties of heavily Bi-doped PbTe p–n homojunction diode grown by liquid-phase epitaxy

“…The wavelength originating from the band gap also shifts to 5.75 lm at 77 K, corresponding to an energy gap of 27 meV. On the other hand, the donor-acceptor pair binding energy of nearest Bi-Bi lattice sites in PbTe diodes heavily doped with Bi was estimated as 23-28 meV in our previous study [4]. Since both sets of results are in strong agreement, we propose that the peak shift observed in the current study originates from the DA pairs at nearest-neighbor Bi-Bi lattice sites.…”

“…The photocurrent density of the heavily Bi-doped sample is approximately 20 times and 3 times greater than that of the undoped sample and heavily In-doped sample, respectively. Since PbTe systems are characterized by a high electric constant (e = 1400-1800) [11], we previously assumed that the high Bi concentration induced strong self-compensation, reducing the number of free electrons and the wide depletion layer [4,5]. Moreover, the free electrons in the n-type layer absorb less infrared radiation in heavily Bi-doped materials than in the other evaluated materials.…”

“…In particular, we studied the behavior of dopant impurities (such as thallium, bismuth and indium) in PbTe bulk crystal and the epitaxial layer [4][5][6][7]. Our previous studies also reported the electrical and optical properties of heavily Bi-doped (Bi concentration x Bi % 2 Â 10 19 cm À3 ) n-PbTe and Tl-doped p-PbTe epitaxial layers grown by TDM-CVP LPE [4,5]. We proposed that a Bi donor atom forms a donor-acceptor (DA) pair with a neighboring or near-neighbor Bi acceptor atom.…”

“…We proposed that a Bi donor atom forms a donor-acceptor (DA) pair with a neighboring or near-neighbor Bi acceptor atom. Such DA pairs cause no effective ionic scattering and form no deep level at high Bi concentrations [4,5]. In the present study, we fabricate and investigate a mid-infrared photodiode based on heavily Bi-doped PbTe, and determine its characteristics.…”

PbSnTe double-hetero junction laser diode and its application to mid-infrared spectroscopic imaging

“…We have developed the temperature-difference method under controlled vapor pressure (TDM-CVP) liquid phase epitaxy (LPE) [1][2][3][4] for the fabrication of these devices [5][6][7]. Whereas, PbTe and PbSnTe based laser diodes (LDs) have been fabricated using a slow-cooling LPE method [8,9], the difficulties have arisen in accurate control of stoichiometry and alloy compositions, because the growth temperature is changed during epitaxial growth.…”