Current SWIR sensor technologies are extremely expensive technology because (1) SWIR-sensitive III-V compound semiconductors ALWAYS require an expensive epitaxial growth process only suitable for small area applications, (2) the epitaxial-grown SWIR photodetector MUST be pixelized by a complicated expensive semiconductor photolithography process, and (3) the SWIR photodetector pixel arrays MUST be connected to Si-based readout integrated circuits (ROIC) by problematic chip bonding processes for making IR imaging, thus resulting in the tremendous price of more than $20,000. Due to this traditional ROIC integration method which is very challenging to make compact and lightweight sensors with fine pixel size, furthermore, the final SWIR sensors are bulky and heavy, resulting in a limited pixel resolution of below 1M pixels. Therefore, the applications of the traditional SWIR sensors have been severely limited. In this proposal, we would like to develop compact, lightweight, high-resolution, ultralow-cost organic light-emitting diode (OLED)-based short wave infrared (SWIR) image sensor by using an innovative optical ROIC integration approach. In this unique OLED-based SWIR image sensors, inexpensive Commercial-Off-The-Shelf (COTS) visible image sensors like a complementary metal-oxide-semiconductor (CMOS) will be used as low-cost readout integrated circuit (ROIC). Our innovative OLED-based SWIR sensor structure does NOT require expensive epitaxial film deposition processes, expensive semiconductor photolithography pixelation processes, and problematic chip bonding processes. This revolutionary OLED-based SWIR image sensors will be fabricated by simply stacking a SWIR sensitive OLED only optically (not electronically) on an inexpensive COTS visible image sensor like a CMOS image sensor. A SWIR sensitive OLED can convert a SWIR image to a visible image without pixelation in the device. A SWIR sensitive OLED is basically an OLED with an epitaxial-free solution-processed PbS colloidal quantum dot (CQD) as the SWIR sensitizing layer and only emits visible light under SWIR illumination. In this novel OLED-based SWIR image sensor structure, the SWIR sensitive OLED will function as the thin layer to convert invisible SWIR images to visible images because the total thickness of the SWIR sensitive OLED is extremely thin (< 500 nm) compared to a pixel size (at least over few ?m) of a visible image sensor. The converted visible images will then be captured as they are by an inexpensive COTS visible image sensor without an additional focus lens because the thickness of a dielectric interlayer between a SWIR sensitive OLED and a visible image sensor will be significantly thinner (<200 nm) than a pixel size (at least over few ?m) of a visible image sensor. Therefore, this unique optical ROIC integration approach enables us to make a high-resolution (> over 100 M pixels) SWIR (0.7-3 ?m) image sensor at a significantly low-cost (<$500).
