Ultraviolet Detectors Based on Ultraviolet–Ozone Modified Hydrogenated Diamond Surfaces

Photodetectors based on interdigitated fingers have been fabricated on hydrogen terminated diamond surfaces. These devices show weak photocurrent-to-dark current ratio (PDR∼10 -2 ) and persistent photoconductivity making them inappropriate for ultraviolet (UV) detection applications despite high deep UV photocurrent (∼10 -4 A) and a spectral discrimination ratio (210/630 nm) of 10 5 . However, an original approach combining the previous hydrogen terminated diamond surface with subsequent controlled UV–ozone post-treatments has allowed to respectively enhance the PDR and the discrimination ratio by more than 7 and 2 orders of magnitude while keeping in the same time a high value of deep UV photocurrent (10 -7 –10 -8 A).