Review of Photon-to-Photon Conversion in Nanoscale Materials and Devices and Its Applications

The photon-to-photon conversion process has attracted great attention as it can carry out the conversion of photons in different wavelength regions and use the characteristics of different bands to achieve a variety of applications, including solar cells, temperature measurement, information security, luminous display, and biomedicine. According to the process of converting photons of different energy, the photon-to-photon conversion process can be simply divided into two categories: the downconversion process converting high-energy photons to lower-energy photons and the upconversion process converting the low-energy photons to higher-energy photons. Nanoscale materials and devices used in photon-to-photon conversion have been widely concerned and have been successfully applied in many fields, while the corresponding summaries of the representative work are very few as far as we know. In this review, recent advances and progress in photon-to-photon conversion in nanoscale materials and devices and their applications are summarized. Around this field, we then analyzed and summarized the prospects and challenges for its development in the future.