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In this article, we study the effect of the inversion charge ( Q _inv ) in a solar cell based on the hole-selective characteristic of substoichiometric molybdenum oxide (MoO_x ) and vanadium oxide (VO_x ) deposited directly on n-type silicon. We measure the capacitance–voltage ( C – V ) curves of the solar cells at different frequencies and explain the results taking into account the variation of the space charge and the existence of Q_inv in the c-Si inverted region. The high-frequency capacitance measurements follow the Schottky metal–semiconductor theory, pointing to a low inversion charge influence in these measurements. However, for frequencies lower than 20 kHz, an increase in the capacitance is observed, which we relate to the contribution of the inversion charge. In addition, applying the metal–semiconductor theory to the high-frequency measurements, we have obtained the built-in voltage potential and show new evidence about the nature of the conduction process in this structure. This article provides a better understanding of the transition metal oxide/n-type crystalline silicon heterocontact., Comunidad de Madrid, Fondo Europeo de Desarrollo Regional (Unión Europea), Ministerio de Ciencia e Innovación (España), Agencia Estatal de Investigación (España), European Social Fund (Unión Europea), Depto. de Estructura de la Materia, Física Térmica y Electrónica, Fac. de Ciencias Físicas, TRUE, pub

CRUE-CSIC (Acuerdos Transformativos 2021) The authors acknowledge the "CAI de Tecnicas Fisicas", the "CAI de Difraccion de Rayos X '' of Universidad Complutense de Madrid, and "Laboratorio de Caracterizacion de Superficies" of CENIM for sample fabrication, GIXRD and XPS measurements, respectively. Also we acknowledge J. Gandia for his support in the analysis of the optical measurements. This work is part of the project MADRID-PV2 (P2018/EMT-4308) funded by the Comunidad Autonoma de Madrid with the support from FEDER Funds, project TEC2017-84378-R, funded by MICINN and European Social Fund, and projects SCCell (PID2020-116508RB-I00) , HyperPHIR (PID2020-117498RB-I00) and SCALED (PID2019-109215RB-C42) , funded by the Spanish Ministry of Science and Innovation. D.Pastor acknowledges financial support from the MEC to the program Ramon y Cajal (No. RYC-2014-16936) . D. Caudevilla would also acknowledge grant PRE2018-083798, financed by MICINN and European Social Fund., This article studies the physical and electrical behavior of indium tin oxide layers (ITO) grown by an unconventional technique: High Pressure Sputtering (HPS), from a ceramic ITO target in a pure Ar atmosphere. This technique has the potential to reduce plasma induced damage to the samples. The aim is to obtain, at low temperature via HPS, good quality transparent conductive oxide layers for experimental photovoltaic cells with emerging selective contacts such as transition metal oxides, alkaline metal fluorides, etc. We found that the resistivity of the films was strongly dependent on Ar pressure. To obtain device-quality resistivity without intentional heating during deposition a pressure higher than 1.0 mbar was needed. These films deposited on glass were amorphous, presented a high electron mobility (up to 45 cm2V- 1s- 1) and a high carrier density (2.9 x 1020 cm-3 for the sample with the highest mobility). The optimum Ar pressure range was found at 1.5-2.3 mbar. However, the resistivity degraded with a moderate annealing temperature in air. Finally, the feasibility of the integration with photovoltaic cells was assessed by depositing on Si substrates passivated by a-Si:H. The film deposited at 1.5 mbar was uniform and amorphous, and the carrier lifetime obtained was 1.22 ms with an implied open circuit voltage of 719 mV after a 215 degrees C air anneal. The antireflective properties of HPS ITO were also demonstrated. These results show that ITO deposited by HPS is adequate for the research of solar cells with emerging selective contacts., Ministerio de Ciencia e Innovación (MICINN)/ESF, Ministerio de Ciencia e Innovación (MICINN), Comunidad de Madrid/FEDER, Depto. de Estructura de la Materia, Física Térmica y Electrónica, Fac. de Ciencias Físicas, TRUE, pub

Se deposita la versión posprint del artículo, In the scope of supersaturated semiconductors for infrared detectors, we implanted Si samples with Ti at high doses and processed them by rapid thermal annealing (RTA) to recover the crystal quality. Also, for comparative purposes, some samples were processed by pulsed-laser melting. We measured the electronic transport properties at variable temperatures and analyzed the results. The results indicate that, for RTA samples, surface layers with a high Ti concentration have negligible conductivity due to defects. In contrast, the implantation tail region has measurable conductivity due to very high electron mobility. This region shows the activation of a very shallow donor and a deep donor level. While deep levels have been previously reported for Ti in Si, such a shallow level has never been measured, and we suggest that it originates from Ti-Si complexes. Finally, a decoupling effect between the implanted layer and the substrate seems to be present, and a bilayer model is applied to fit the measured properties. The fitted parameters follow the Meyer–Neldel rule. The role of the implantation tails in Si supersaturated with Ti is revealed in this work., Comunidad de Madrid, ERDF Funds - MICINN, European Social Fund (ESF), Ministerio de Ciencia e Innovación (España), Mexican grants program CONACyT, Ministry of Education in the Kingdom of Saudi Arabia, Depto. de Estructura de la Materia, Física Térmica y Electrónica, Fac. de Ciencias Físicas, TRUE, pub