Several decades ago, it was proposed that one could improve the single junction solar cell by the concentration of effort onto the hot carriers. In the intervening years, no significant progress has been made in this direction, although the effort continues to involve a large body of workers. While this community is focused on the role of phonons and selectively measuring only a fraction of the energy spectrum, it has not generally addressed the true usage of the hot carriers that can be supported in the system. Here, we discuss a different approach relying upon the use of 'metastable' levels provided by the satellite valleys of the conduction band. Such usage retains the hot carriers at higher energy levels than normal, and promises to provide the long-sought improvement with hot carrier solar cells.

https://iopscience.iop.org/article/10.1088/1361-6641/ab0bc3/pdf

In search of a true hot carrier solar cell

Beyond 3rd generation solar cells and the full spectrum project. Recent advances and new emerging solar cells

Hot charge carriers (HC) are photoexcited electrons and holes that exist in nonequilibrium high-energy states of photoactive materials. Prolonged cooling time and rapid extraction are the current challenges for the development of future innovative HC-based optoelectronic devices, such as HC solar cells (HCSCs), hot energy transistors (HETs), HC photocatalytic reactors, and lasing devices. Based on a thorough analysis of the basic mechanisms of HC generation, thermalization, and cooling dynamics, this review outlines the various possible strategies to delay the HC cooling as well as to speed up their extraction. Various materials with slow cooling behavior, including perovskites and other semiconductors, are thoroughly presented. In addition, the opportunities for the generation of plasmon-induced HC through surface plasmon resonance and their technological applications in hybrid nanostructures are discussed in detail. By judiciously designing the plasmonic nanostructures, the light coupling into the photoactive layer and its optical absorption can be greatly enhanced as well as the successful conversion of incident photons to HC with tunable energies can also be realized. Finally, the future outlook of HC in optoelectronics is highlighted which will provide great insight to the research community.

/pdf/there-is-plenty-of-room-at-the-top-generation-of-hot-charge-ilfslp3vkz.pdf

There is plenty of room at the top: generation of hot charge carriers and their applications in perovskite and other semiconductor-based optoelectronic devices

Uncovering the charge transfer and recombination mechanism in ZnS-coated PbS quantum dot sensitized solar cells

Hot carrier solar cells hold the promise of efficiency significantly greater than that predicted by the Shockley–Queisser limit. Consequently, there has been considerable effort to create cells that achieve this goal, but so far, this has not been realized. There are many reasons for this. Here, the principles of the concept will be discussed along with some myths that hinder the future development of such devices. Also, a new approach to the hot carrier solar cell is described along with some recent experimental results that support such an approach.

R. Linke

Papers

Hot carrier solar cell with semi infinite energy filtering