Abstract The epitaxial lift‐off (ELO) technique can be used to separate a III–V solar cell structure from its underlying GaAs or Ge substrate. ELO 4‐inch wafers is shown and 2‐inch wafer reuse after demonstrated without degradation in performance of the subsequent thin‐film cells that were retrieved it. Since basic wet chemical smoothing etch procedure appeared insufficient remove all surface contamination, re‐preparation done by chemo‐mechanical polishing procedure. Copyright © 2010 John...

Abstract The present work describes the study and improvement of Epitaxial Lift‐Off (ELO) technique, which is used to separate III/V device structures from their GaAs substrates. As a result ELO method, initially able millimetre sized layers with lateral etch rate about 0.3 mm/h, has been developed process capable free entire 2″ epitaxial substrates rates up 30 mm/h. It shown that right deposition strategy, thin‐film can be adequately processed on both sides. In this way semi‐transparent,...

Electromagnetic resonances in conducting structures give rise to the enhancement of local fields and extinction efficiencies. Conducting are conventionally fabricated with a fixed geometry that determines their resonant response. Here, we challenge this conventional approach by demonstrating photo-generation THz linear antennas on flat semiconductor layer structured optical illumination through spatial light modulator. Free charge carriers photo-excited only selected areas, which enables...

Abstract Thinning down the absorber layer of GaAs solar cells can reduce their cost and improve radiation hardness, which is important for space applications. However, lighttrapping schemes necessary to achieve high absorptance in these be experimentally challenging or introduce various parasitic losses. In this work, a facile light‐trapping approach based on wet chemical etching demonstrated. The rear‐side contact ultrathin wet‐chemically textured between local Ohmic points using an...

Epitaxial, boron-doped diamond films were grown by hot-filament-assisted chemical vapour deposition (CVD) on (100) and (110) natural substrates. Resistivity measurements for 10 K<T<500 K showed a clear transition from band to hopping conduction upon lowering of temperature. In the regime, had higher conductivity than samples. The reverse was found in regime. This is explained difference crystal growth mechanisms, leading boron concentrations lower carrier mobilities samples oriented films....

III-V semiconductor light-emitting diodes (LEDs) are a promising candidate for demonstrating electroluminescent cooling. However, exceptionally high internal quantum efficiency designs paramount to achieving this goal. A significant loss mechanism preventing unity in GaAs-based devices is nonradiative surface recombination at the perimeter sidewall. To address issue, an unconventional LED design presented, which distance from central current injection area device's extended while maintaining...

Centimeter sized, crack-free single crystal InGaP films of 1 μm thickness were released from GaAs substrates by a weight-induced epitaxial lift-off process. At room temperature, the lateral etch rate process as function applied Al0.85Ga0.15As release layer was found to have maximum 3 mm/h at nm. Using 5-nm-thick AlAs layers, increased exponentially with temperature up 11.2 80 °C. Correlation experimental data established theoretical description indicate that model is qualitatively correct...

The influence of junction depth in III–V solar cell structures was investigated for GaAs and InGaP cells. Typical cells employ a shallow design. We have shown that both types, deep close to the back structure performs better than At maximum power point operate mainly radiative recombination regime, while non‐radiative is dominant. steeper slope IV curve boosts fill‐factor by 3–4%, which thereby most improved parameter. In order minimize collection losses upper part cell, optimal thickness...

Abstract The effects of electron irradiation on the performance GaAs solar cells with a range architectures is studied. Solar shallow and deep junction designs processed native wafer as well into thin‐film were irradiated by 1‐MeV electrons fluence up to 1×10 15 e − /cm 2 . degradation cell due was studied experimentally theoretically using model simulations, coherent set minority carriers' lifetime damage constants derived. primarily depends depth thickness active layers, whereas material...

In this study a recently developed physics-based model to describe the performance degradation of GaAs solar cells upon electron irradiation is applied analyze effects proton irradiation. For purpose with significantly different architectures are subjected range fluences up 5×1012 H+/cm2. The resulting J−V and EQE characteristics measured compared simulations from model. requires individual constants for SRH lifetimes surface recombination velocities as an input. these were obtained...

Abstract By reducing the thickness of absorber layers, ultrathin GaAs solar cells can be fabricated in a more cost‐effective manner using less source material and shorter deposition times. In this work, are presented with diffuse scattering layer based on wide bandgap GaP grown directly device layers MOCVD. The roughness surface morphology quantified atomic force microscopy resulting capability is assessed wavelength‐dependent reflectance measurements. Ohmic rear contacts made contact points...

In the present work space compatibility of thin-film GaAs solar cells is studied. These are separated from their substrate by epitaxial lift-off (ELO) technique and mounted behind a CMG cover glass which at same time serves as stable carrier for thin film cells. initial stage development these have an average efficiency about 15·4% under AM0 illumination due to not yet optimized grid contacts anti-reflection coatings. Inspection after irradiation 1 MeV electrons, thermal vacuum cycling...

We report properties of long-range-ordered ${\mathrm{GaInP}}_{2}$ alloys as a function temperature by combination photoreflectance (PR), photoluminescence (PL), and Hall--van der Pauw measurements. Below T=200 K the optical transport are strongly influenced donor state, which, owing to confinement in ordered domains, has large binding energy 36 meV. Evidence for strong localization was obtained T30 K: PR spectra showed pronounced first-derivative line shape at same where PL emission occurs,...

The epitaxial lift-off process allows the separation of a thin layer III/V material from substrate by selective etching an intermediate AlAs with HF. In theory proposed for this process, it was assumed that every mole dissolved three moles gas are formed. order to verify assumption reaction mechanism and stoichiometry were investigated in present work. solid, solution gaseous products etch have been examined number techniques. It found aluminum fluoride is formed, both solid form as well...

The epitaxial lift-off (ELO) process is utilized to produce thin-film III-V devices, while the substrate (GaAs wafer) on which structure was grown can be reused. However, so far direct reuse of these GaAs wafers inhibited by remnants wafer surface that cannot removed in a straightforward fashion utilizing general cleaning methods. Therefore, etching hydrofluoric acid investigated microscopic techniques, profilometry and X-ray photoelectron spectroscopy. It found immediately after covered...