CAREER: Environmentally Stable Electrically Pumped Perovskite Laser

Non-technical description:Photonic integrated circuits (ICs) have enabled many applications such as optical communication, bio-sensing, and quantum communication. To utilize the full functionality of photonic ICs, integrated electronic-photonic circuits are demanded, an essential component of which is an economical, silicon-compatible, and electronically addressable laser in the photonic IC. In the visible wavelengths, although epitaxially grown III-N semiconductors are the main gain medium candidate for on-chip lasers, they lack silicon-compatibility and is expensive. This proposal explores solution-processed metal-halide perovskites as alternative gain media and develops perovskite laser diodes on the silicon platform. By judiciously engineering the gain medium composition and band alignment of carrier transport layers with perovskite gain, employing defect-passivation, and designing for low-threshold laser cavities, environmentally stable perovskite laser diodes can be realized. The family of perovskite lasers developed in this program will enable efficient and low-cost integrated photonic solutions for confocal microscopy, on-chip fluorescent sensing, and flow cytometry in the bio-photonics area, as well as visible light communication and on-chip quantum emitters in the optical communication area. It will also help closing the “green gap” where conventional epitaxially grown inorganic semiconductors suffer from low efficiencies, and advance the field of solution-processed semiconductor lasers. The educational portion of the program aims to increase public awareness of photonics and to pipeline qualified students to help advance the U.S. photonics industry.Technical description:A crucial yet unavailable component in high-performance visible-wavelength photonic ICs and other chip-scale photonic systems is a silicon-compatible on-chip laser that is efficient, stable, economical, and electronically addressable. So far, III-N lasers are the main candidates, but their material platform requires complex epitaxial growth and lattice constant matching to the silicon substrate. Although solution-processed metal-halide perovskites have been suggested as alternative gain media, and many perovskite lasers have been demonstrated so far, all perovskite lasers to date are optically pumped. Additionally, they operate under ultrafast pulsed pumping and/or at cryogenic temperatures and have a short lifetime. This program starts by developing economical, environmentally stable and silicon-compatible perovskite lasers that operate under continuous wave optical pumping at room temperature. This can be achieved by directly patterning perovskite into high-Q laser resonators with the manufacturing friendly nanoimprint lithography, then defect-passivating the perovskite with polycarbonate. This program further aims to demonstrate electrically pumped perovskite lasers through band alignment tailoring of carrier transport layers for efficient current injection, perovskite-polymer blending for minimal leakage current, low-loss electrode formation to reduce wasteful non-radiative recombination at electrodes, and low-threshold laser cavity design. This work will not only lead to the insertion of perovskite lasers into functional photonic ICs, but also the long-sought-after realization of solution-processed laser diodes. On a more system level, this work will enable the connectivity between the photonic “plane” and electronic “plane” in multi-functional adaptive photonic/electronic integrated systems.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.