Self-Powered Perovskite Photon-Counting Detector Arrays for Low-Power Optical Interconnects

Self-Powered Perovskite Photon-Counting Detector Arrays for Low-Power Optical Interconnects The rapid growth of artificial intelligence and cloud computing is increasing the amount of information that must move between processors, memory, and servers. Conventional copper connections consume substantial electrical power and generate heat as data rates increase, creating a major obstacle to faster and more energy-efficient computing systems. Optical interconnects, which transmit information using light, offer a promising alternative, but their receivers still require highly sensitive detector arrays that can operate with very little power and reliably detect extremely weak optical signals. This project will develop self-powered detector arrays made from metal halide perovskites, a class of semiconductor materials that can efficiently convert light into electrical signals. The detectors will be designed to operate without an applied voltage and to recognize optical data symbols containing only a few photons. Reducing the number of photons needed to transmit each bit of information could lower the power required by light sources, decrease heat generation, and improve the energy efficiency of data centers and future artificial-intelligence hardware. The project will also advance understanding of noise and defects in emerging semiconductor materials, train graduate and undergraduate students in materials science, electronics, and photonics, and expand research opportunities for undergraduate students. The resulting knowledge may also benefit weak-light sensing technologies used in medical imaging, light detection and ranging, scientific instruments, quantum information systems, and radiation detection. The project will establish a materials-to-systems framework for zero-bias metal halide perovskite photon-counting detector arrays for short-range optical interconnects. Its central objective is to determine how shallow electronic traps, unintended electrical doping, and defects at material interfaces generate dark counts and limit the minimum detectable photon number. Cryogenic thermally stimulated photoemission and device-level electrical reemission measurements will quantify trap energy, density, carrier-capture cross section, and thermal emission rate, allowing specific defect populations to be linked directly to detector-noise events. Controlled introduction and compensation of extrinsic impurities and self-doping will test whether doping-induced carrier emission contributes to noise. Detector performance will then be improved through absorber-composition selection, grain-size control, thin-film engineering, surface and grain-boundary passivation, and dedoping. The separation of scalable manufacturing studies from high-speed receiver-physics studies will clarify the material and device requirements for future heterogeneous integration with complementary metal-oxide-semiconductor or silicon-germanium receiver electronics. The intellectual contribution will be a quantitative connection among defect energetics, spontaneous charge emission, detector noise, photon-number sensitivity, and optical-link performance. 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.