BACKGROUND:  Infrared photodetectors are photonic devices that are sensitive to infrared radiation (IR). Organic PDs have been the subject of extensive research in the past decade and are a promising alternative to conventional inorganic PDs. Efficient, fast response and low working voltage IR photodetectors (PDs) are highly desired for many applications such as imaging, sensing, and communications, but efficient IR PDs based on organic materials has not been demonstrated. The fast response time expands the range of working frequency limit for IR PDs and the low voltage further reduces power consumption and allows fore ease of integration with inorganic electrical components. The invention described here is an organic IR PD using low-cost solution processing that exhibits fast response time, low working voltage, and high efficiency.

INNOVATION:  The invention utilizes a new low band gap (LBG) polymer and a long pass filter. The polymer compositions were strategically designed for proper energy level matching and good solubility and processibility, yielding an external quantum efficiency exceeding 40%, frequency roll-off of 4MHz, and very low dark currents.

POTENTIAL APPLICATIONS:  Scientific, industrial, and commercial applications, such as remote control, chemical/biological sensing, imaging, optical communications, and spectroscopic and medical instruments.

ADVANTAGES

• Large-area detection
• Wide selection of materials that allows color tuning
• Low cost fabrication on flexible substrates
• High external quantum efficiency
• Full-color
• Fast-response and low working voltage, which stands in sharp contrast to existing organic infrared photodetectors
• Position-sensitive photodetectors

DEVELOPMENT-TO-DATE:  The invention has been developed and performance metrics have been characterized.

Reference: UCLA Case No. 2007-308