Giant photovoltaic response in band engineered ferroelectric perovskite

Subhajit Pal; Atal Bihari Swain; Pranab Parimal Biswas; D Murali; Arnab Pal; B Ranjit K Nanda; Pattukkannu Murugavel

doi:10.1038/s41598-018-26205-x

Giant photovoltaic response in band engineered ferroelectric perovskite

Sci Rep. 2018 May 22;8(1):8005. doi: 10.1038/s41598-018-26205-x.

Authors

Subhajit Pal¹, Atal Bihari Swain¹, Pranab Parimal Biswas¹, D Murali¹, Arnab Pal¹, B Ranjit K Nanda², Pattukkannu Murugavel³

Affiliations

¹ Department of Physics, Indian Institute of Technology Madras, Chennai, 600036, India.
² Department of Physics, Indian Institute of Technology Madras, Chennai, 600036, India. nandab@iitm.ac.in.
³ Department of Physics, Indian Institute of Technology Madras, Chennai, 600036, India. muruga@iitm.ac.in.

Abstract

Recently the solar energy, an inevitable part of green energy source, has become a mandatory topics in frontier research areas. In this respect, non-centrosymmetric ferroelectric perovskites with open circuit voltage (V_OC) higher than the bandgap, gain tremendous importance as next generation photovoltaic materials. Here a non-toxic co-doped Ba_1-x(Bi_0.5Li_0.5) _x TiO₃ ferroelectric system is designed where the dopants influence the band topology in order to enhance the photovoltaic effect. In particular, at the optimal doping concentration (x _opt ~ 0.125) the sample reveals a remarkably high photogenerated field E_OC = 320 V/cm (V_OC = 16 V), highest ever reported in any bulk polycrystalline non-centrosymmetric systems. The band structure, examined through DFT calculations, suggests that the shift current mechanism is key to explain the large enhancement in photovoltaic effect in this family.