Abstract Triple‐junction GaInP/GaAs/GaInNAs solar cells with conversion efficiency of ~29% at AM0 are demonstrated using a combination molecular beam epitaxy (MBE) and metal‐organic chemical vapor deposition (MOCVD) processes. The bottom junction made GaInNAs was first grown on GaAs substrate by MBE then transferred to an MOCVD system for subsequent overgrowth the two top junctions. process produced repeatable cell characteristics uniform pattern over 4‐inch wafers. Combining advantages...

Abstract We report on the progress in developing lattice‐matched GaAs‐based solar cells with focus AlGaInP, AlGaAs, and GaInNAsSb materials, aiming at achieving a wide spectral coverage, that is, 0.7–2.2 eV. To this end, we first benchmark performance of an upright four‐junction GaInP/GaAs/GaInNAsSb/GaInNAsSb grown by molecular beam epitaxy p‐GaAs substrates bandgaps 1.88, 1.42, 1.17, 0.93 eV, respectively. The cell exhibited efficiency ~39% 560‐sun illumination while showing good electrical...

We report the temperature coefficients for MBE-grown GaInP/GaAs/GaInNAsSb multijunction solar cells and corresponding single junction sub-cells. Temperature-dependent current-voltage measurements were carried out using a simulator equipped with 1000 W Xenon lamp three-band AM1.5D simulator. The triple-junction cell exhibited an efficiency of 31% at AM1.5G illumination 37–39% 70x real sun concentration. external quantum was also measured different temperatures. up to 80°C, open circuit...

Abstract Monolithic four‐junction solar cells incorporating two dilute nitride (GaInNAsSb) bottom junctions are reported. The have band gaps of 0.9 and 1.2 eV, while the top 1.4 1.9 eV. By using experimental‐based parametrization, it was estimated that cell could theoretically exhibit efficiency levels 34.7% at one sun, 43.2% 100 suns, 46.4% 1000 suns for AM1.5D illumination. most challenging subcell in terms fabrication is GaInNAsSb junction with eV gap. For this subcell, a background...

We report on the fabrication of diffraction gratings for application as back contact reflectors. The are designed thin-film solar cells incorporating absorbers with bandgap slightly lower than GaAs, i.e. InAs quantum dot or GaInNAs cells. Light trapping in enables increase absorption leading to higher short circuit current densities and efficiencies. study metal/polymer reflectors half-sphere, blazed, pyramid gratings, which were fabricated either by photolithography nanoimprint lithography....

This work aims to quantify the effect of a diamond-like carbon coating (DLC) treatment aramid fibres and reveal conversion fibre-level performance leap on macroscale mechanical behaviour. The DLC-based is applied directly reinforcement laminates are infused with an epoxy matrix. After characterisation coated surfaces, composite analysed via interlaminar shear testing, fatigue testing damage tolerance microbond tests, 3D finite element simulation using cohesive zone model interface. results...

The effect of a Ag/Cu-based double-layer back reflector on current generation in GaInNAs single-junction solar cell is reported. Compared to Ti/Au reflector, the use Ag/Cu led 28% enhancement short-circuit density, attaining value ∼14 mA/cm2 at AM1.5D (1000 W/m2) under GaAs filter. enhanced line with requirements for current-matching GaInP/GaAs/GaInNAs triple-junction cells. reflectors also had low contact resistivity order 10−6 Ω·cm2 and none samples exhibited notable peeling metals...

Quantum dot solar cells are promising for next-generation photovoltaics owing to their potential improved device efficiency related bandgap tailoring and quantum confinement of charge carriers. Yet implementing effective photon management increase the absorptivity dots is instrumental. To this end, performance thin-film InAs/GaAs with planar structured back reflectors reported. The experimental exhibited a bandgap-voltage offset 0.3 V an open circuit voltage 0.884 V, which one highest values...

Several passivation techniques are developed and compared in terms of their ability to preserve the optical properties close-to-surface InAs/GaAs quantum dots (QDs). In particular, influence N-passivation by hydrazine chemical treatment, followed atomic layer deposition (ALD) AlO x use AlN deposited plasma-enhanced ALD reported. The effectiveness is benchmarked measuring emission linewidths decay rates photo-carriers for near-surface QDs. All three mechanisms resulted reducing oxidation Ga...

Low-bandgap GaInNAsSb single junction solar cells incorporating a planar Au back surface reflector for enhancing the photocurrent generation are reported. In particular, 700 nm thick with bandgap of 0.78 eV (corresponding to 6.2% N) exhibited short-circuit current density 15.2 mA/cm2 AM1.5D (1000 W/m2) illumination, when placed underneath GaAs-filter mimicking operation multijunction architecture. The corresponding external quantum efficiency represents highest reported so far dilute nitride...

A new method for modification of planar multilayer structures to create nanostructured aluminum oxide anti-reflection coatings is reported. The non-toxic and low-cost, being based on treatment the coating with heated de-ionized water after deposition oxide. results show that provides a viable alternative attaining low reflectance ARC. In particular, average reflectivity ∼3.3% demonstrated in broadband spectrum extending from 400 nm 2000 ARCs deposited GaInP solar-cells, typical material used...

Dilute nitride arsenide antimonide compounds offer widely tailorable band-gaps, ranging from 0.8 eV to 1.4 eV, for the development of lattice-matched multijunction solar cells with three or more junctions. Here we report on performance GaInP/GaAs/GaInNAsSb cell grown by molecular beam epitaxy. An efficiency 27% under AM0 conditions is demonstrated. In addition, was measured at different temperatures. The short circuit current density exhibited a temperature coefficient 0.006 mA/cm2/°C while...

Etching characteristics of lattice-matched GaInP/GaAs/GaInNAsSb heterostructures by aqueous solutions iodic acid (HIO3) and hydrochloric (HCl) is reported. The study aims at optimization mesa fabrication process involved in the development III‒V multijunction solar cells. effects temperature, agitation, etchant composition, illumination on etching selectivity are investigated. Varying composition agitation rate room temperature results various sidewall morphologies, ranging from rough...

We report the effects of back surface reflectors on quantum efficiency single-junction 1 eV GaInNAs solar cells. For cells with Au reflector, an average external 72% was achieved between 920 nm and 1250 nm. The internal cell over 90% for same wavelength range. highest short-circuit current density calculated from a reflector 12.8 mA/cm2, which is 17% higher than what obtained using conventional Ti/Au metallization. This would enable fabrication GaInP/GaAs/GaInNAs at least 30% AM1.5G.

We report on the fabrication of InAs/GaAs quantum dot solar cells with high open circuit voltage by molecular beam epitaxy. `Shallow' and `deep' junction architectures were compared. The highest 0.94 V was obtained for `shallow' configuration. InAs decreased only ~40 mV compared to GaAs reference both indicating quality dots. also found be dependent size

We report on the development of light-trapping architectures applied to thin-film solar cells. In particular, we focus enhancing absorption at 1-eV spectral range for dilute nitride and quantum dot materials influence planar back reflectors photovoltaic properties. Moreover, discuss properties polymer diffraction gratings with enhanced capability pointing advantageous pyramidal gratings. order understand suitability these grating space applications, have performed an electron irradiation...

We report on the performance of front contact grids based Ag, Al, and Au applied to III-V multijunction solar cells. compare their suitability as grid metals from different perspectives, including price, mass-to-conductivity ratio, abundance. The functionality was evaluated by performing charge transport experiments under simulated sunlight. best cell obtained for Ag contacts. On other hand, Al provide most cost-effective approach: when compared Au, cost material equal conductivities is only...

A lattice-matched four-junction solar cell on a GaAs substrate, for space applications, is demonstrated. The incorporates MBE grown GaInP, GaAs, GaInNAsSb and junctions with band-gaps of 1.9 eV, 1.4 1.2 eV 0.9 respectively. For AMO illumination, the exhibited maximum efficiency 27%. this performance, high collection bottom required. current generation primarily enabled by achieving very low background doping level (~ 5×10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML"...

We report on the fabrication, characterization and simulation of diffraction gratings for back contact reflectors in III-V solar cells. The are designed thin-film cells incorporating absorbers with bandgap slightly lower than GaAs, such as InAs/GaAs quantum dot or GaInNAs Metal/polymer a blazed grating pyramid were fabricated by nanoimprint lithography. compared terms ability, which is feature responsible increasing absorption. showed higher light to grating. efficiency measurements...

We report on the progress made in development of lattice-matched multijunction solar cells employing dilute nitride sub-cells. In particular, we upright four-junction architecture with bandgaps 0.9 eV, 1.2 1.4 eV and 1.9 The cell includes two sub-junctions. This structure exhibited an efficiency 29% at 1-sun AM1.5D illumination, which is highest level reported for such so far. addition, developing materials a bandgap down to 0.7 enable fabrication highly efficient five- or six-junction GaAs....