Publication:
Indium tin oxide obtained by high pressure sputtering for emerging selective contacts in photovoltaic cells

Research Projects
Organizational Units
Journal Issue
Abstract
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.
Description
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.
Unesco subjects
Keywords
Citation
Collections