Correlation of Pr, Dy, and Tb addition with physical properties of InP layers prepared by liquid phase epitaxy

Abstract

The characterisation of thick (>10 µm) InP layers prepared by liquid phase epitaxy with Pr, Dy and Tb rare earth element (REE) addition in the growth melt for applications in radiation detector structures is reported. A significant improvement of all the studied parameters with increasing concentration of REE up to critical value (0.25 wt%) was observed. The structural defect density was reduced by one order of magnitude and the residual impurity concentration by three and a half order of magnitude (< 10 15 cm -3). The conductivity has been changed from n to p-type when REE exceeded certain concentration limit in the melt (0.15 wt% for Pr, 0.05 wt% for Tb and 0.03 wt% for Dy). The low-temperature photoluminescence (PL) spectra narrowed and the corresponding fine lines were resolved. Comparison of PL peaks of n and p-type conducting layers with the obtained electrical data leads to the conclusion that the dominant acceptor impurity for the n to p-type crossover is Ge for Pr addition and Mn for Tb and Dy addition.

Effect of Fe inter‐diffusion on properties of InP layers grown with addition of RE elements

“…Two series of InP layer samples with and without of thin (~ 1 µm) buffer undoped InP layer were LPE grown from the liquid phase with addition of rare earths. Previous experience has been used to select suitable RE elements that could be helpful in the preparation of high structural quality InP layers with residual undesirable electrical active impurities ≤ 10 15 cm -3 [7]. Pr, Tb, Dy, and Tm have been chosen for typical behaviour.…”

Optical properties of InP layers prepared with the addition of Ce, Tm and Lu in the growth melt

“…It has been demonstrated that the admixture of Pr, Tb, Dy and Yb leads, at certain concentrations, to the reversal of InP conductivity type from n to p. Dy was shown [14] to produce the conductivity conversion at lowest concentration thus giving the best opportunity to grow thick, pure and structurally perfect layers. Detailed studies of the temperature-dependent Hall effect and lowtemperature photoluminescence (PL) enabled to identify the dominant acceptors responsible for the conductivity crossover in the case of Pr, Tb and Yb additions.…”