Высокотемпературная диффузия акцепторной примеси Ве в AlN

The high-temperature diffusion of an acceptor impurity of beryllium (Be) into bulk single-crystal aluminum nitride (AlN) has been studied. It is shown that the introduction of Be leads to the appearance of green luminescence of AlN, which is stable at room temperature and is observed over the entire thickness of the sample. It was shown by the method of luminescence analysis that the Be diffusion process is most efficiently realized in the temperature range from 1800°C to 2100°C and is characterized by extremely high diffusion coefficients D = 10-7 cm2/s and 10-6 cm2/s, respectively. It is shown that a prolonged diffusion process (t ≥ 1 hour) at a temperature of 2100°C leads to concentration quenching of the luminescence of near-surface AlN layers with a thickness of ≈ 80 μm, which makes it possible to estimate the concentration of beryllium impurities in the near-surface layer on the order of 10E19 cm-3.

Влияние акцепторной примеси бериллия на оптические свойства монокристаллического AlN

The effect of high-temperature (T = 1880 ° C) diffusion of beryllium ions on the properties of single-crystal aluminum nitride is investigated. It was shown that postgrowth doping of AlN with beryllium compensates the small silicon donor centers entering the AlN lattice in an uncontrolled manner during growth. It was established that the introduction of Be into the AlN lattice leads to a decrease in the optical absorption of the latter in the visible and ultraviolet ranges. The totality of the results is explained by a shift in the position of the Fermi level, caused by the introduction of the acceptor impurity of beryllium, towards the ceiling of the AlN valence band.

Механизм генерирования донорно-акцепторных пар при сильном легировании n-ZrNiSn акцепторной примесью Ga

The nature of the mechanism of the simultaneous generation of donor–acceptor pairs under heavy doping of n -ZrNiSn intermetallic semiconductor with the Ga acceptor impurity is established. Such spatial arrangement in the crystal lattice of ZrNiSn_1– x Ga_ x is found when the rate of movement of the Fermi level εF found from calculations of the density distribution of electron states coincides with that experimentally established from dependences lnρ(1/ T ). It is shown that when the Ga impurity atom (4 s ^24 p ^1) occupies the 4 b sites of Sn atoms (5 s ^25 p ^2), structural defects of both acceptor nature and donor nature in the form of vacancies in the 4 b site are simultaneously generated. The results are discussed in the scope of the Shklovskii–Efros model of a heavily doped and compensated semiconductor.

Features of Structural, Electrokinetic, and Energy State Characteristics of ZrNiSn1-xGax Solid Solution

Features of structural, electrokinetic, and energy state characteristics of ZrNiSn1-xGax semiconductive solid solution were investigated in the temperature ranges Т = 80 - 400 K and х = 0 - 0.15. Disorder of crystal structure for n-ZrNiSn compound as a result of occupation of Zr (4d25s2) atoms in 4a sites by Ni (3d84s2) ones up to ~ 1 % was confirmed. It generated donor levels band ɛD1 in the band gap. It was shown that introduction of Ga (4s24p1) atoms by means of substitution of Sn (5s25p2) ones ordered crystal structure. In this case acceptor defects were generated in 4b sites and it created extended acceptor impurity band ɛА. It was suggested that with generation of acceptor structural defects the vacancies in the Sn (4b) atomic sites simultaneously generated donor defects and formed deep donor band ɛD2 (donor-acceptor pair took place).