February 2016

Researchers at the University of California at Berkeley and the Lawrence Berkeley National Lab have made novel high-performance and robust lasers from caesium lead halide perovskites nanowires, that could be used in on-chip photonic and spectroscopic applications, such as optical communications, imaging and sensing. The lasing color of the devices can also easily be tuned from green to blue by changing the halide ion.

Nanowire lasers show great promise as miniaturized light sources for optoelectronics. Since they act as both the laser cavity and gain medium, nanowires can be easily incorporated into electronic circuits. Optical gain is the ability of a material to 'amplify' light or to generate more photons than the number of photons it absorbs. A typical laser usually consists of a gain medium encased in an optical cavity containing two opposing mirrors. The gain medium contains two electronic energy levels, and the lower energy level naturally contains more electrons than the upper level. However, by exciting the cavity ' either electrically or by using light ' some electrons can be 'pumped' into the upper state.

Researchers from the Universitat Jaume I and the Universitat de València have studied the interaction of two materials, halide perovskite and quantum dots, revealing significant potential for the development of advanced LEDs and more efficient solar cells.

The researchers quantified the "exciplex state" resulting from the coupling of halide perovskites and colloidal quantum dots. Both known separately for their optoelectronic properties, but when combined, these materials yield longer wavelengths than can be achieved by either material alone, plus easy tuning properties that together have the potential to introduce important changes in LED and solar technologies.

Dyesol, global leader in the development and commercialization of Perovskite Solar Cells (PSC), has announced that it has appointed VDL Enabling Technologies Group to assist in the development of a Major Area Demonstration Prototype.

The 1st Phase contract involves a specialist engineering study resulting in the preparation of a Feasibility & Functional Specification for Perovskite Major Area Demonstrator development. This phase will be conducted over a 4 month period commencing immediately. It is expected that upon the successful completion of the initial study, a 2nd Phase of design and development will follow, and the 3rd Phase will be Realization. The 3 phase project is expected to be completed in the 1st half of 2017.

Researchers at EPFL have designed an ultra-sensitive carbon nanotube-based photodetector, sensitized with perovskite nanowires which make it highly responsive.

While carbon nanotubes are often used in photovoltaic and optoelectronic devices, light detection with pristine carbon-nanotube field-effect phototransistors is currently limited to the range of 10% quantum efficiency (the responsivity of the best carbon nanotube devices is around 0.1 A/W). Using perovskites, EPFL scientists have now fabricated a carbon-nanotube photodetector with responsivity as high as 7.7×105 A/W.