Dominant acceptors in Li doped, magnetron deposited Cu2O films

M Nyborg,E Monakhov,K Karlsen,K Bergum

doi:10.1088/2053-1591/ac3e24

Abstract

Cu2O films deposited by reactive magnetron sputtering with varying Li concentrations have been investigated by a combination of temperature-dependent Hall effect measurement and thermal admittance spectroscopy. As measured by secondary ion mass spectrometry, Li concentrations up to 5 × 1020 Li/cm3 have been achieved. Li doping significantly alters the electrical properties of Cu2O and increases hole concentration at room temperature for higher Li concentrations. Moreover, the apparent activation energy for the dominant acceptors decreases from around 0.2 eV for undoped or lightly doped Cu2O down to as low as 0.05 eV for higher Li concentrations.

Highlights

Cuprous oxide (Cu2O) is an attractive p-type semiconductor widely investigated for its possible application in photovoltaics
We report on the electronic properties of the dominant acceptors in Li doped, magnetron sputter deposited Cu2O films
Temperature-dependent hall effect Hall effect measurements, performed for the Cu2O films deposited on the quartz substrates, from the polarity of the Hall voltage it is revealed p-type conductivity in all the samples [17]

Summary

Introduction

Cuprous oxide (Cu2O) is an attractive p-type semiconductor widely investigated for its possible application in photovoltaics. The samples with the longest Na indiffusion exhibited degenerated p-type conduction This is a surprising result since Na, similar to Li, is expected to passivate VCu and reduce hole concentration. The observed increase in hole concentration was attributed to an excess formation of VCu compensating for Na atoms incorporated at the interstitial site as donors [15]. Such an interpretation, cannot explain the decrease in the acceptor activation energy, since the acceptor activation energy of VCu is believed to be ∼0.2 eV [12]. For the first time temperature dependence of hole concentration and the activation energy of the dominant acceptors are deduced using TDH measurements and thermal admittance spectroscopy (TAS) on Li doped Cu2O

Experimental

Results and discussion

Conclusion

Data availability statement