Role of f-Elements in the Growth of InP Layers for Radiation Detectors

2005

phys. stat. sol. (c)

Self Cite

This contribution reports the redistribution behaviour of Fe during the growth of InP layers from liquid phase with addition of some rare earth elements on semi‐insulating InP:Fe substrates. We have studied the influence of different rare earths on the Fe diffusion into InP layer and compared it with the phenomenon of an extraction of iron from Fe doped materials into adjacent layers doped by Zn, Cd and Be, reported recently. In the case of Tm addition a conversion of electrical conductivity of InP layer to semi‐insulating as a consequence of Fe diffusion has been observed while no significant Fe inter‐diffusion has been confirmed in the presence of other investigated rare earth additions. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

“…The typical layer thickness was about 10 µm. The details of the technology were described elsewhere [8]. Metallic RE elements were analysed by atomic emission spectroscopy.…”

Section: Methodsmentioning

confidence: 99%

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

2005

phys. stat. sol. (c)

Self Cite

“…for allowing electrons and holes, originating from the electron-hole pairs created during the radiation impact, to reach collecting electrodes. As suggested earlier [1] the preparation of Schottky type collecting (and/or blocking) contacts would be of great advantage for performance of detectors. At present Schottky contacts on the p-type InP could be prepared with large height and low leakage current which could not be reached on the n-type InP.…”

Section: Introductionmentioning

confidence: 91%

“…The expected gettering effect [2] has been observed for all RE used, however their purifying efficiency and their influence on the growth rate varied considerably for individual RE species [1,3]. It has been observed that the admixture of certain RE causes not only substantial reduction of residual shallow impurities but also conversion of electrical conductivity from n to p type [1,3]. Among the studied RE elements only Yb and Ce have been incorporated into InP lattice and at the same time doping by these elements leads to the conversion of the conductivity from n to p type.…”

Section: Introductionmentioning

confidence: 99%

Ce and Yb doped InP layers grown for radiation detection

Phys. Status Solidi (c)

et al. 2007

Self Cite

InP single crystals were grown by liquid phase epitaxy on semi-insulating InP:Fe substrate with cerium (Ce) and ytterbium (Yb) additions to the growth melt. Grown layers were characterised by Hall measurements and low temperature photoluminescence spectroscopy. Both types of layers exhibit the change of electrical conductivity from n to p type. Ce and Yb have been found to be incorporated into the InP lattice since a sharp luminescence lines arising from inner shell transitions of Yb 3+ and Ce 3+ were detected at 1002 and 3534 nm, respectively. A metastable conductivity state of InP:Ce layers has been found at temperatures below 35 K, a phenomenon previously reported for InP:Yb layers. Similar electrical behaviour of InP (Ce, Yb) layers leads us to conclude that Ce acts as dominant acceptor impurity responsible for n→p conductivity change.

“…The possibility to use these elements as efficient agents in removing undesirable residual impurities was suggested a long time ago [1] and revisited recently [2][3][4][5]. REEs have been also reported as scavenging agents tying up both n and p-type impurities [6].…”

Section: Introductionmentioning

confidence: 99%

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

et al. 2003

phys. stat. sol. (c)

Self Cite

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.