21 February 2019
Fast, sensitive photodetectors
Published online 27 November 2015
Scientists have made stable, highly light-sensitive crystals.
A research team from Saudi Arabia and Canada ‘grew’ light-sensitive single crystals of methylammonium lead bromide, with potential optoelectronic properties.
“These crystals, easy to scale up over an area of tens of square of centimetres, could potentially be used to fabricate high-performance commercial photodetectors," says lead researcher Osman Bakr from King Abdullah Institute of Science and Technology (KAUST), Saudi Arabia.
The scientists synthesized the crystals—also known as planar-integrated single-crystal perovskites—through a solution-processed method at room temperature. They exhibited steady-state absorption and photoluminescence at ambient conditions and under a humidity level of 57 per cent, showing no noticeable changes in their stability for over a month1.
They also showed high charge-carrier mobility and long charge-carrier diffusion lengths that exceed other types of semiconductor films.
These crystals also possessed low trap density, a property that impedes transport of charges. It’s what gives them the potential to be used in optoelectronic devices where controlling trap density in a material is a prerequisite for most device applications.
When a layer of the crystals on a specific substrate was exposed to light, the crystals generated a considerable amount of photocurrent by responding fast to a broad range of frequencies of light, the researchers say.
- Saidaminov, M. I. et al. Planar-integrated single-crystalline perovskite photodetectors. Nature Commun. 6, 8724 (2015).