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We report thin-film InAs/GaAs quantum dot (QD) solar cells with n − i − p + deep junction structure and planar back reflector fabricated by epitaxial lift-off (ELO) of full 3-in wafers. External quantum efficiency measurements demonstrate twofold enhancement of the QD photocurrent in the ELO QD cell compared to the wafer-based QD cell. In the GaAs wavelength range, the ELO QD cell perfectly preserves the current collection efficiency of the baseline single-junction ELO cell. We demonstrate by full-wave optical simulations that integrating a micro-patterned diffraction grating in the ELO cell rearside provides more than tenfold enhancement of the near-infrared light harvesting by QDs. Experimental results are thoroughly discussed with the help of physics-based simulations to single out the impact of QD dynamics and defects on the cell photovoltaic behavior. It is demonstrated that non radiative recombination in the QD stack is the bottleneck for the open circuit voltage ( V oc ) of the reported devices. More important, our theoretical calculations demonstrate that the V oc offset of 0.3 V from the QD ground state identified by Tanabe et al., 2012, from a collection of experimental data of high quality III-V QD solar cells is a reliable – albeit conservative – metric to gauge the attainable V oc and to quantify the scope for improvement by reducing non radiative recombination. Provided that material quality issues are solved, we demonstrate – by transport and rigorous electromagnetic simulations – that light-trapping enhanced thin-film cells with twenty InAs/GaAs QD layers reach efficiency higher than 28% under unconcentrated light, ambient temperature. If photon recycling can be fully exploited, 30% efficiency is deemed to be feasible.

[EN] The effects of the offset level and of the doping level in the perovskite layer upon both the reverse saturation current (J0) and the series resistance (Rs) of p-p-n perovskite solar cells have been researched in this paper, using five different materials such as spiro-OMeTAD, Cu2O, CuSCN, NiO and CuI, as Hole Transporting Material (HTM). The analysis was carried out by means of the single and double-diode models of a solar cell and of genetic algorithms based on optimization technique, in order to extract the desired parameters. The minor degradation of J0 and Rs has been found for the condition offset equal to zero and for the highest doping level in p-type perovskite layer. Also, a comparison has been made of the behavior of two reverse saturation currents (J01 and J02). The power conversion efficiency (PCE) has shown to be more strongly dependent on J02 than on J01. Results obtained in this work can be used to improve the manufacturing process of these devices., This work was partially supported by the National Council Research (CONICET), Argentina, by the Universidad Nacional Arturo Jauretche, Argentina, by the Universidad Nacional de Quilmes, Argentina, by the Universidad Nacional de La Plata, Argentina and by the Ministerio de Economía y Competitividad (Grant ENE2016-77798-C4-2-R), Spain

[EN] In this paper, a theoretical study of different p-p-n perovskite solar cells has been performed by means of computer simulation. Effects of the offset level upon the power conversion efficiency (PCE) of these devices have been researched using five different materials such as spiro-OMeTAD, Cu2O, CuSCN, NiO and CuI, as Hole Transporting Layer (HTL). The Solar Cells Capacitance Simulator (SCAPS)-1D has been the tool used for numerical simulation of these devices. A strong dependence of PCE has been found with the difference between the Maximum of the Valence Band of the HTL and perovskite materials, and with the doping level in p-type perovskite layer. A minimum value of hole mobility in the HTL has been also found, below which the PCE is reduced. Efficiencies in the order of 28% have been obtained for the Cu2O/Perovskite/TiO2 solar cell. Results obtained in this work show the potentiality of this promising technology., This work was partially supported by the Universidad Nacional de Quilmes, Argentina, by the Universidad Nacional Arturo Jauretche, Argentina, by the Universidad Nacional de La Plata, Argentina, by the National Council Research (CONICET), Argentina, and by the Ministerio de Economia y Competitividad (Grant ENE2016-77798-C4-2-R), Spain.

This paper presents a theoretical study of the effect of the nature of the carrier escape from quantum dots (QDs) on the performance of InAs/GaAs QD solar cells (QDSCs), based on numerical simulations. Excitonic and non-excitonic dynamics of electrons and holes are considered in the modeling, by assuming identical or separate time constants for the intersubband carrier transfer processes in the ground and excited states. It is shown that the excitonic capture and escape allow us to explain the non-additive characteristic of the QD photocurrent, observed when the total photocurrent of the cell is much lower than the sum of the photocurrents contributed separately by the barrier and the nanostructures. This behavior is practically eliminated in the non-excitonic case. The correlated dynamics under the non-excitonic scenario is analyzed by calculating the device sensitivity to small changes introduced in the escape time of electrons. It is stated that the non-variation of the QD photocurrent with this parameter could be interpreted as a consequence of either a correlated electron-hole escape from QDs, or a dominant recombination over the other involved processes. The ideality factor of the different QDSCs studied is also calculated from simulations under both concentrated sunlight and dark conditions. The obtained results are in line with experimental measurements published in the literature.

This paper presents a theoretical study about quantum dot solar cells by means of numerical simulations, considering different doping levels in the intrinsic region of the cells, with the aim of evaluating the effect on the device's power conversion efficiency. Results of simulations performed over GaAs solar cells with InAs quantum dots, based on two different fabrication processes, are reported. The donor doping density in the intrinsic region was ranged from 1013 to 1017 cm-3. It is shown that, for a doping level of 7×1015 cm-3, the contribution of larger sized quantum dots to the photocurrent is increased by 50%, a very promising result in the search for new designs with higher efficiencies. Fil: Cedola, Ariel Pablo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de la Plata. Facultad de Ingeniería. Departamento de Electrotecnia. Grupo de Est.s/materiales y Disposit.electronicos; Argentina Fil: Gioannini, Mariangela. Politecnico di Torino; Italia Fil: Cappelluti, Federica. Politecnico di Torino; Italia Fil: Cappelletti, Marcelo Ángel. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de la Plata. Facultad de Ingeniería. Departamento de Electrotecnia. Grupo de Est.s/materiales y Disposit.electronicos; Argentina Fil: Peltzer y Blanca, Eitel Leopoldo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de la Plata. Facultad de Ingeniería. Departamento de Electrotecnia. Grupo de Est.s/materiales y Disposit.electronicos; Argentina

The radiation resistance in InGaP/GaAs/Ge triple-junction solar cells is limited by that of the middle GaAs sub-cell. In this work, the electrical performance degradation of different GaAs sub-cells under 1 MeV electron irradiation at fluences below 4 × 1015 cm−2 has been analyzed by means of a computer simulation. The numerical simulations have been carried out using the onedimensional device modeling program PC1D. The effects of the base and emitter carrier concentrations of the p- and n-type GaAs structures on the maximum power point have been researched using a radiative recombination lifetime, a damage constant for the minority carrier lifetime and carrier removal rate models. An analytical model has been proposed, which is useful to either determine the maximum exposure time or select the appropriate device in order to ensure that the electrical parameters of different GaAs sub-cells will have a satisfactory response to radiation since they will be kept above 80% with respect to the non-irradiated values. Fil: Cappelletti, Marcelo Ángel. Universidad Nacional Arturo Jauretche; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentina. Universidad Nacional de La Plata. Facultad de Ingeniería. Departamento de Electrotecnia; Argentina Fil: Cedola, Ariel Pablo. Universidad Nacional de La Plata. Facultad de Ingeniería. Departamento de Electrotecnia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentina Fil: Peltzer y Blanca, Eitel Leopoldo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentina. Universidad Nacional de La Plata. Facultad de Ingeniería. Departamento de Electrotecnia; Argentina

A theoretical study of the electrical performance of p-on-n GaAs sub-cells under AM0, irradiated with 1 MeV electrons, has been carried out by means of computer simulation. Effects of both base and emitter carrier concentration upon radiation resistance of these devices have been researched. From analysis it is possible to determine the highest electron fluence to which the electrical parameters of the solar cell, with well-known base and emitter carrier concentrations, are reduced simultaneously in less than 20% from their non-irradiated values. Results presented in this paper are important in order to contribute to the design of radiation-hardened devices.

The performance of crystalline silicon n + / p / p + and n / n / p + solar cells under AM0 spectrum,irradiated with 1 MeV electrons at fluences below 10 17 cm −2 has been analyzed by means ofcomputer simulation. The software used, fully developed by the authors, solves numerically inone dimension under steady-state conditions, the Poisson and continuity equationsself-consistently. The influence of constructive characteristics and different levels of hazardousenvironmental work conditions on the maximum power point of over 150 devices has beeninvestigated. The study has allowed the authors to propose a useful analytical model related tothe constructive characteristics of the device such as polarity, base resistivity and totalthickness, with the aim of examining the electrical performance of Si space solar cells. Resultspresented in this paper are important in order to contribute to the design of radiation-hardeneddevices. 1. Introduction Taking into account the urgent need to make the most ofalternative energy sources, the study of semiconductor devicesthatcanprovidepoweratlowoperatingcost,suchassolarcells,is extremely important at the present time. Deep studies aboutso-calledthirdgenerationsolarcells,focusedonnewmaterialsand technologies such as intermediate band, quantum dots andhot-carrier devices [1–4], are being carried out with the aimof reducing the cost and increasing the efficiency with respectto the first generation, i.e. crystalline silicon (c-Si) solar cells.However, in present times a considerable amount of researchin the field of the photovoltaic cells is still dominated by theconventional c-Si devices.For space power applications, where the devices areexposed to irradiation of high energy particles, multijunction(MJ) solar cells based on III–V technologies havedemonstrated higher conversion efficiencies and radiation-resistance than c-Si devices [5–7]. Nevertheless, c-Si solarcells have proven to offer a worthy operational reliability andcosteffectivenessasaspacepowersource[8–10]andthereforefurther research in this topic is still required.Every different solar cell structure from a given material,total thickness, base resistivity and polarity (p- or n-type),is expected to respond differently as a function of radiation.Therefore, each device must undergo some kind of irradiationtest to determine the degradation characteristics. Nowadays,precise techniques of modeling and simulation have becomefundamental tools to predict and to improve the responseof electronic devices under different operation conditions,offering valuable knowledge at a much lower cost and in lesstime than experimentation.In order to contribute to the design of radiation-hardeneddevices, this paper presents a theoretical study of the behaviorof different c-Si n