The electron effective masses for Al0.15Ga0.35In0.5P and Ga0.5In0.5P have been investigated using conventional and optically detected cyclotron resonance. For AlGaInP (partly ordered) it is determined to be m*=(0.14±0.01) m0. For disordered GaInP the mass is found to be m*=(0.092±0.003) m0 and for ordered material (band gap reduction ∼50 meV) m*=(0.088±0.003) m0. The experimentally deduced values are compared with those obtained from five-band k⋅p calculation.

The formation of parasitic GaxIn1−xAsyP1−y intermediate layers when growing GaAs on GaInP or vice versa by MOVPE is investigated by the use of asymmetric GaInP/GaAs/AlGaAs double heterostructures. We found that such intermediate layers are only formed when growing GaAs on GaInP (inverted interface), but not for the reverse case (normal interface), resulting in a strong photoluminescence peak below the GaAs band gap. Time-resolved photoluminescence also indicates a much shorter minority carrier lifetime of the structures containing the inverted GaInP/GaAs interface (∼10 ns) compared to samples containing the normal interface (∼0.5 μs). By investigation of the interface of GaInP/AlGaAs and AlGaInP/GaAs, it is found that In carry-over is mainly responsible for the formation of this layer in our system. By growing thin AlGaAs intermediate layers (1 to 2 nm) at the inverted interface, this low-energy photoluminescence peak could be effectively suppressed. The same could be obtained without any special means in a smaller epitaxial system, probably due to the reduced hot susceptor surface.

A nearly damage-free dry etching process in the material system AlGaInP/GaInP is demonstrated. An electron cyclotron resonance (ECR) ion source has been used for plasma excitation. Photoluminescence spectroscopy at varying excitation power densities and sample temperatures is used to measure the degree of damage.

Strained GaInP single quantum wells with AlGaInP barriers have been grown by MOVPE and characterized by HRXRD. The influence of strain in these quantum wells has been examined by photoluminescence. The PL-intensity of single quantum wells at 300K increases for compressive strain. When the critical thickness is reached, the intensity drops drastically. PL-energies at 300K are in good agreement to theory, however at low temperatures we observed a shift below the theoretical values for strained material. In contrary to unstrained quantum wells, the emission-energy of strained quantum wells shows an anomalous increase of up to 40meV when raising the temperature from 2 to 150K and a shift of 60meV with excitation power. In addition, time-resolved measurements on these samples show a nonexponential decay of emission for temperatures below 150K, indicating various decay mechanisms.

Direction-dependent transition matrix elements are calculated as a function of strain and superlattice ordering for GaInP using a 6 x 6 LK Hamiltonian. The predicted direction dependence is in excellent agreement with the measured polarization of laser emission from broad-area strained GaInP QW lasers. Lasers with cavities oriented along the [011] direction lase with a polarization direction tilted towards the ordering planes. Lasers with [011BAR]-oriented stripes and disordered structures emit with the conventional TE or TM slab-waveguide polarization normally expected for strained-layer lasers.

Strained GaInP quantum wells with AlGaInP barriers have been grown by metalorganic vapor phase epitaxy (MOVPE). The influence of strain in single quantum wells on the optical properties is examined by photoluminescence. The emission energy of strongly compressively strained quantum wells shows an anomalous temperature dependence and a shift of 13 meV per decade of excitation power. This is interpreted as an accurate measure of the critical strain where strain relaxation occurs. By varying growth temperature and substrate orientation, the influence of ordering in strained and unstrained quantum wells is examined. Whereas unstrained quantum wells show a similar band gap reduction as bulk GaInP, this is significantly weakened in strained quantum wells. This has two reasons. For one, the degree of ordering is limited due to unequal Ga and In amounts. Additionally, according to Wei et al. [Appl. Phys. Lett. 64 (1994) 757], a further reduction is expected if the joint influence of strain and ordering is taken into account.

Ordered and disordered (AlxGa1−x)0.5In0.5P (x=0, 0.33, 0.66) layers have been grown on GaAs by metalorganic vapor phase epitaxy. The complex refractive index below and above the band edge has been determined by transmission experiments and ellipsometry. We have observed, that ordered and disordered samples only differ near the fundamental band gap with respect to these properties.

Ga0.5 In0.5 P has been investigated using optically detected cyclotron resonance and photoluminescence techniques. For the disordered alloy, the electron mass is determined to m*=0.092 m0, and for ordered material (band gap reduction ~ 50 meV) the value m*=0.088 m0 is found. The experimentally deduced values are compared with those obtained from a five-band kp calculation.

Ordered and disordered GaInP layers have been grown by MOVPE. The complex refractive index below and above the band edge has been determined by applying conventional absorption spectroscopy, transmission experiments and ellipsometry. We have observed that ordered and disordered samples only differ near the fundamental band gap with respect to these properties, whereas at higher energies, no differences could be detected.

This paper demonstrates the suitability of Ar ion beam etching (Ar-IBE) to realize nanometer structures in the material system AlGaInP/GaInP. The influence of aluminium content, ion energy and angle of incidence of the ions on the etch rate is investigated. Furthermore we show some examples of pattern transfer realized in AlGaInP/GaInP using Ar-IBE.

Undoped and Se-doped Ga0.51In0.49P/GaAs single heterojunctions grown by metalorganic vapor-phase epitaxy (MOVPE) are characterized with deep-level transient spectroscopy and transmission electron microscopy (TEM). The undoped MOVPE material, grown at 710 °C, is characterized by a deep electron trap with an activation energy that takes values in the range 700–900 meV. Se doping suppresses the formation of this trap when the doping level is higher than 5×1017 cm−3. Furthermore, Se doping suppresses the persistent photoconductivity that is observed in the undoped samples. Finally, analysis with cross-section TEM reveals that the samples undergo partial spinodal decomposition in a direction nearly vertical to the interface.

Using time-resolved photoluminescence, we have examined the photoluminescence (PL) decay time of ${\mathrm{Ga}}_{1\mathrm{\ensuremath{-}}\mathit{y}}$${\mathrm{In}}_{\mathit{y}}$P/(${\mathrm{Al}}_{\mathit{x}}$${\mathrm{Ga}}_{1\mathrm{\ensuremath{-}}\mathit{x}}$${)}_{1\mathrm{\ensuremath{-}}\mathit{y}}$${\mathrm{In}}_{\mathit{y}}$P single quantum wells with various well widths and different Al content in the barriers. At low temperatures, we find an increase of the lifetime with increasing temperature in good agreement with the temperature dependence of radiative recombination. At a characteristic temperature, which depends on the quantum-well thickness, a drop of the PL lifetime is observed. The temperature dependence can be explained by simultaneous thermal emission of electrons and holes out of the quantum wells. We find that the activation energy ${\mathit{E}}_{\mathit{a}}$ is equal to one-half of the total confinement energy \ensuremath{\Delta}E of the electron-hole pair in the quantum well and can be explained on the basis of Boltzmann statistics assuming thermal equilibrium between quantum-well and barrier states during the recombination.

We report on investigations of dry etching in GaInP/AlGaInP. As a method of dry etching we used CCl2F2/Ar reactive ion etching (RIE) and Ar ion beam etching (IBE). The suitability of these two methods for microstructure technology with respect to etch rates in investigated. First data on damage resulting from application of these two dry etching techniques in GaInP/AlGaInP are presented. The degree of damage was detected by performing photoluminescence measurement.

Optically detected microwave-induced impact ionization of excitons and shallow donors is studied in Yb-doped InP grown by metalorganic chemical vapor deposition. The experimental results directly confirm that Yb3+ intrashell emission is induced by nonradiative recombination of Yb bound excitons due to an impurity Auger effect. Yb3+ ions in InP are found to bind excitons with the electron being localized first, followed by subsequent hole capture.

The two novel liquid In precursors TMIn-HNiPr2 and (3-dimethylaminopropyl)dimethylindium (DADI) were synthesized and their behaviour in the MOVPE growth of InP studied. Layers with low temperature mobilities in excess of 100,000 cm2/V·s could be grown. When growing GaInAs, some side reactions between TMIn-HNiPr2 and AsH3 were observed, which did not significantly affect the layer quality. DADI could be used in combination with tertiarybutylphosphine resulting in acceptable InP quality at moderate growth temperatures.

The effects of hydrostatic pressure on the InP:Yb luminescence were explored using a gasketed diamond anvil cell (DAC). The pressure dependence of the Yb3+ luminescence shows a small positive shift (0.96 meV/GPa) at low pressures (< 4 GPa) and a negative one (-0.04 meV/GPa) above 4 GPa. The spectra of the Yb3+ emission differ markedly in these two pressure ranges. It was concluded that intra-4f-shell transitions of the Yb3+ on indium substitutional (T(d)) site dominate in the spectrum above 4 GPa, whereas at lower pressures the emission has a different nature.