Science Daily April 19, 2018 In solar cells the spectral position of the window of light that can be efficiently converted is strongly related to its band-gap. Researchers in Germany measured the charge carrier density created by the absorption of multiple photons in perovskite nanocrystals. The efficiency of this process becomes drastically enhanced when the frequency of the primary light oscillation and frequency of the exciton at the band-gap become equal. The observation of this novel resonance phenomenon for optical excitations in excitonic semiconductors could pave the way for solar cells to more efficiently convert long-wavelength light into usable electric […]
Tag Archives: Solar energy
Sunlight funnel collects light from all directions
Physorg March 1, 2018 Researchers in Germany modeled the new light-harvesting funnels on nature’s design. The devices consist of many randomly oriented “donor” pigments that can absorb light from nearly all incident angles and funnel it onto a smaller number of “acceptor” molecules that are all oriented in a single direction to direct the light onto a photoconversion device. This concept can reduce the intrinsic losses of previous solar concentrators to below 10%. In tests the solar concentrator absorbed approximately 99% of the incident light, with minimal losses due to reabsorption and reflection. The device also has a light redirection […]
Innovative diode design uses ultrafast quantum tunneling to harvest infrared energy from the environment
Phys org February 5, 2018 Researchers in Saudi Arabia have designed a device, rectenna, that can tap into the infrared radiation in the environment and waste heat from industrial processes and transform quadrillionth-of-a-second wave signals into useful electricity. Tunneling devices, such as metal-insulator-metal (MIM) diodes, rectify infrared waves into current by moving electrons through a small barrier. They used a ‘bowtie-shaped’ nano-antenna that sandwiches the thin insulator film between two slightly overlapped metallic arms to generate the intense fields needed for tunneling… read more.
Fully screen-printed monoPoly silicon solar cell technology
Source: Phys.org, December 14, 2017 The technology developed by researchers in Singapore is applicable on both p-type and n-type silicon wafers, features homogenous junctions and standard fire-thorough screen-printed metal contacts with grids on both sides, resulting in a high-efficiency bifacial solar cell. It uses an advanced tunnel oxide and doped silicon layers, enabling excellent surface passivation in the non-contact cell regions along with very low-resistance and low-recombination screen-printed contacts. Using commercially available large-area Cz-Si wafers they recorded an average cell efficiency of 21.5%… read more.