Smooth pyroelectric luminescence in β-BaB2O4 single crystals via Fowler-Nordheim tunneling Mohamed Swaisi, Rajesh Katoch, Andreas Dörfler and Andreas Ruediger EPL, 136 6 (2021) 67002 Published online: 24 March 2022 DOI: 10.1209/0295-5075/ac195f