III–V nanowire structures are among the promising material systems with applications in hot carrier solar cells. These nanostructures can meet requirements for such photovoltaic devices, i.e., suppression of thermalization loss, an efficient transport, and enhanced photoabsorption thanks to their unique one-dimensional (1D) geometry density-of-states. Here, we investigate effects spatial confinement photogenerated carriers InGaAs-InAlAs core–shell nanowires, which presents ideal class cell...

Hot electrons established by the absorption of high-energy photons typically thermalize on a picosecond time scale in semiconductor, dissipating energy via various phonon-mediated relaxation pathways. Here it is shown that strong hot carrier distribution can be produced using type-II quantum well structure. In such systems dominant thermalization process limited radiative recombination lifetime with reduced wavefunction overlap holes. It proposed subsequent reabsorption acoustic and optical...

InAs/AlAs$_{x}$Sb$_{1-x}$ quantum wells are investigated for their potential as hot carrier solar cells. Continuous wave power and temperature dependent photoluminescence indicate a transition in the dominant relaxation process from conventional phonon-mediated below 90 K to regime where inhibited radiative recombination dominates at elevated temperatures. At temperatures measurements consistent with type-I that exhibit hole localization associated alloy/interface fluctuations....

One of the main loss mechanisms in photovoltaic solar cells is thermalization photogenerated hot carriers via phonon-mediated relaxation. By inhibiting these relaxation and reducing losses, it may be possible to improve power conversion efficiency beyond single gap limit. Here, type-II InAs/AlAsSb multi-quantum well (MQW) structures are investigated study impact phononic properties AlAsSb barrier material carrier thermalization. Experimental theoretical results show that by increasing...

One-dimensional structures such as nanowires (NWs) show great promise in tailoring the rates of hot carrier thermalization semiconductors with important implications for design efficient absorbers. However, fabrication defect-free crystal and control their intrinsic electronic properties can be challenging, raising concerns about role competing radiative non-radiative recombination mechanisms that govern effects. Here, we elucidate impact purity altered on by comparing two classes III–V...

The temperature dependence of a InAs/AlAs0.84Sb0.16 multi-quantum-well sample is studied using continuous wave photoluminescence. An “s-shape” shift in peak energy observed and attributed to low localization states. High incident power density photoluminescence measurements were performed probe the nature such localization. results opposed possibility type-II band structure supported idea effect on hot carriers our system was an improvement their stability due hole mobility at elevated presented.

Abstract An InGaAsP quantum well with a type‐II band alignment is studied using continuous wave power and temperature dependent photoluminescence (PL) spectroscopy. The small energy separation between the ground state first excited results in significant thermal carrier redistribution occupation, particularly, increasing excitation temperature. This filling evident as high‐energy shoulder PL spectra, same region where simplest Planck‐description gradient considered inversely proportional to...

Hot-carrier solar cells offer the opportunity to harvest more energy than limit set by Shockley–Queisser model reducing losses due thermalization of photo-generated carriers. Previous reports have shown lower rates in thinner absorbers, but origin this phenomenon is not precisely understood. In work, we investigate a series ultrathin GaAs absorber layers sandwiched between AlGaAs barriers and transferred on host substrates with gold back mirror. We perform power-dependent photoluminescence...

The effect of carrier–carrier and carrier–phonon interactions is presented in n = 1 (2D) (BA)2PbI4 Ruddlesden–Popper thin films, their compared to that conventional MAPbI3. While temperature-dependent photoluminescence shows the well-studied structural phase transitions evidence longitudinal optical (LO) phonon scattering MPbI3, 2D films produce subtler properties. At low temperatures, two competing intrinsic exciton observed (P1 P3), addition several extrinsic attributed impurities film....

Under continuous-wave laser excitation in a lattice-matched In0.53Ga0.47As/In0.8Ga0.2As0.44P0.56 multi-quantum-well (MQW) structure, the carrier temperature extracted from photoluminescence rises faster for 405 nm compared with 980 excitation, as injected density increases. Ensemble Monte Carlo simulation of dynamics MQW system shows that this rise is dominated by nonequilibrium LO phonon effects, Pauli exclusion having significant effect at high densities. Further, we find fraction carriers...

Observation of robust hot carrier effects in quantum-well structures has prompted hopes to increase the efficiency solar cells beyond Shockley–Queisser limit (33% for single junction at AM1.5G). One main studies is determination temperature, which provides information on thermalization mechanisms carriers semiconductor materials. Here, we investigate spatial distribution photo-generated a InGaAs multi-quantum-well structure via hyperspectral luminescence imaging. We discuss proper methods...

Carrier thermalization in a superlattice solar cell made of polar semiconductors is studied theoretically by considering minimal model where electron-phonon scattering the principal channel carrier energy loss. Of note, effect an intrinsic quantum mechanical property, phonon coherence, on investigated, within semiclassical picture terms wave packet. It turns out that coherent longitudinal optical (LO) phonons weaken effective coupling, thus supposedly lowering carrier-energy-loss rate cell....

Understanding the origin of hot carrier relaxation in nanowires (NWs) with one-dimensional (1D) geometry is significant for designing efficient solar cells such nanostructures. Here, we study influence Auger heating and Shockley-Read-Hall recombination on dynamics catalyst-free InGaAs-InAlAs core-shell NWs. Using steady-state time-resolved photoluminescence (PL) spectroscopy dependences effects degree confinement photogenerated carriers induced by nanowire diameter are determined at...

Hot carrier effect, a phenomenon where charge carriers generated by photon absorption remain energetic not losing much energy, has been one of the leading strategies in increasing solar cell efficiency. Nanostructuring offers an effective approach to enhance hot effect via spatial confinement, as occurring nanowire structure. The recent experimental study Esmaielpour et al. [ACS Applied Nano Materials 7, 2817 (2024)] reveals fascinating non-monotonic dependence array on diameter nanowire,...

In this study, detailed temperature dependent simulations for absorption and photogenerated recombination of hot electrons are compared with experimental data an InAs/AlAsSb multi-quantum well. The describe the actual photoluminescence (PL) observations accurately; in particular, room e1-hh1 simulated transition energy 805 meV closely matches 798 PL spectra, a difference only 7 meV. Likewise, expected separations between local maxima (p1-p2) simulated/experimental spectra have just 2 meV:...

Simultaneous continuous wave (CW) photoluminescence and monochromatic current density-voltage (J-V) measurements of InAs/AlAsSb QW p-i-n diodes reveal stable hot carriers observed at relatively low power (nearly independent power). This behavior is attributed to preferential scattering high energy the upper satellite L- X-valleys, which inhibits carrier thermalization via LO phonon emission. Although both electric field optical excitation are shown enable generation in quantum wells (QWs),...

A type-II InAs/AlAs$_{0.16}$Sb$_{0.84}$ multiple-quantum well sample is investigated for the photoexcited carrier dynamics as a function of excitation photon energy and lattice temperature. Time-resolved measurements are performed using near-infrared pump pulse, with energies near to above band gap, probed terahertz probe pulse. The transient absorption characterized by multi-rise, multi-decay that captures long-lived decay times metastable state an excess-photon $>100$ meV. For...

Abstract Hot carrier solar cells aim to overcome the theoretical limit of single‐junction photovoltaic devices by suppressing thermalization hot carriers and extracting them through energy selective contacts. Designing efficient absorbers requires further investigation on properties in materials. Although is responsible for a large portion loss cells, it still one least understood phenomena semiconductors. Here, impact excitation photo‐generated an InGaAs multi‐quantum well (MQW) structure...

The effect of an InP cap on the photoluminescence (PL) spectrum InGaAsP/InAlAs quantum well (QW) is investigated using excitation power and temperature dependent PL. An as-grown sample with layer shows inverted interface created between InAlAs that has a transition energy very close to QW; consequently, there overlap them. On other hand, QW etched away does not have feature due interface; even at low power, only observed transition.

Silicon (Si) impurities are among the most widely used dopants in GaAs-based electronic and optoelectronic materials, including low-dimensional systems such as nanowires (NWs). Undesired $p$-type conduction is often observed Si-doped GaAs NWs due to amphoteric nature of Si, but can be mitigated by proper catalyst-free, vapor-solid growth processes. Yet, intriguing dynamics Si dopant incorporation spatial distribution within NW structure largely unknown, which key understanding resulting...

A theoretical model using electron-phonon scattering rate equations is developed for assessing carrier thermalization under steady-state conditions in two-dimensional systems. The applied to investigate the hot effect III-V hot-carrier solar cells with a quantum well absorber. question underlying proposed investigation is: what power required maintain two populations of electron and hole carriers quasi-equilibrium state at fixed temperatures quasi-Fermi level splitting? obtained answer that...

Semiconductor nanowires (NWs) have shown evidence of robust hot-carrier effects due to their small dimensions, making them attractive for advanced photoenergy conversion concepts. Especially, indium arsenide (InAs) NWs are promising candidates harvesting hot carriers high absorption coefficient, carrier mobility, and large effective electron-to-hole mass difference. Here, we investigate the cooling recombination dynamics photoexcited in pure passivated InAs by using ultrafast near-infrared...