In this proposed project, we plan to complete the further research and develop of a novel platform solid-state image sensor, Quanta Image Sensor (QIS), for future NASA missions, and other scientific, industrial, and consumer low-light, photon-counting applications. The outcome of this project is a visible-blind UV/EUV photon-counting quanta image sensor with high-speed and accurate photon-counting capability without the necessity of electron avalanche multiplication. The sensor will have a linear multi-bit photon-counting response, among other exciting features, such as up to ~100% duty cycle, zero dead time, low dark count, low operating voltage and power consumption, large format with high spatial resolution, room temperature operation, high quantum efficiency in UV/EUV wavelengths, and strong radiation tolerance. The ultimate goal of this project is to produce a Quanta Image Sensor (QIS) with enhanced quantum efficiency (QE) in UV/EUV wavelengths and high radiation hardness. The R&D work in Phase I provides a fundamental base for this development, and the real device design and fabrication will be completed in Phase II of this project. During Phase II, a second-generation QIS test chip will be designed, fabricated, and tested. The new test chip will serve as a plat-form to demonstrate the proposed new technologies that will bring necessary features to the future NASA applications. If successful, the test chip will significantly improve the readiness level of the QIS technologies and their implementation in NASA applications. A lot of exciting experiments and validation can be conducted based on the test chip both in a laboratory environment and in some space-relevant environments. A camera/imaging system will be built surrounding the new test chip to satisfy the requirements of those validation and experiments. Potential NASA Applications (Limit 1500 characters, approximately 150 words) The applications include a wide range of astrophysics studies. For example, the studies of exoplanet atmospheres, surface reflectance, proto-planets, coronagraph, and the intergalactic and circumgalactic medium. The outcome of this project will benefit the flagship NASA missions such as LUVOIR, HabEx, and ESA-NASA Solar Orbiter. Besides, the potential product will be the only type of detector that can provide the photon number resolving capability to enable accurate UV/EUV quantum yield measurements. Potential Non-NASA Applications (Limit 1500 characters, approximately 150 words) The outcome of this project is beneficial to a wide range of applications. For example, scientific, high-end imaging applications such as life science, fluorescence microscopy, and chemistry studies such as flow cytometry. There are also sizeable markets in medical dermatology imaging, high-resolution surface inspection in automotive and industrial applications, and flame detection.