Our business in QDOF electronics is because we provide significant value to our clients by addressing the unique requirements of their applications. The breadth and depth of our expertise and capabilities have resulted in innovative solutions spanning a wide range of applications. Examples of these application-specific solutions are constantly changing, but the following are current or recent projects in the area of quantum dot, organic, and flexible electronics.
- Directed energy testing
- Displays and lighting
- Implantable devices
We have developed a novel photodiode architecture that provides high quantum yield based on colloidal quantum dot (CQD) absorber layers. The spectral sensitivity of this architecture spans ultraviolet to short-wave infrared (SWIR) wavelengths. It is extremely cost effective, solution processed, and scalable to large area arrays. A critical advantage includes its ability to be directly integrated onto a read out integrated circuit, greatly reducing system complexity and cost. The performance of the devices rivals that of expensive, epitaxial focal planes made from inorganic semiconductors. The combination of high efficiency, broad spectral sensitivity, fast response time, low dark currents, and simple processing could make our QD imaging technology attractive as a low cost alternative for multispectral imaging.
The development of practical devices using colloidal quantum dots (CQDs) has garnered significant attention due to their potential use in low-cost photovoltaic (PV) solar cells. We have developed a simple heterojunction diode structure that takes advantage of the extended infrared spectrally tunable absorption from PbS CQDs. This planar heterostructure has demonstrated a power conversion efficiency of 5.2%, the highest reported value for PV power conversion from a CQD-based device. The cost of materials and fabrication infrastructure is low, and processing is done at room temperature. The material properties suggest ultimate efficiencies >10%, or as high as 15% for tandem architectures, which could significantly alter the price/performance ratio for photovoltaic cells.
Directed Energy Testing
We are working to improve the characterization and test capabilities for directed energy sources. Examples include the use of large-area, flexible substrates to fabricate conformal sensors that measure not only beam profile, but the amount of energy deposited from high-energy laser systems. Similar sensor arrays are used to map the temperature distribution of targets under laser irradiation. In another example, we have developed sensor technologies to simultaneously measure the amount microwave power and subsequent heating caused by microwave exposure. This can be useful for high-power microwave systems as well as medical applications, such as hyperthermia treatments to improve the efficacy of chemotherapy.
Displays and Lighting
Organic light-emitting devices (OLEDs) have become the basis of a multi-billion dollar industry, primarily for displays but with lighting products on the near horizon. A major challenge for OLEDs is their degradation in air, which requires encapsulation and adds cost. While many groups are focusing on improved encapsulation, we have developed OLED devices that can be stored and operated in air with no encapsulation required. These devices have the potential to dramatically reduce the cost of these devices, making them more competitive with LCD displays or fluorescent lighting. Other efforts have led to improved transparent conductors for flexible substrates as well as permeation barrier testing with ultra-high sensitivity.
We have worked in collaboration with Premitec, Inc., to apply our expertise to flexible silicon integration and advance the capabilities of implantable devices. Specifically, we have developed a technology for the integration of flexible CMOS within a biocompatible polymer substrate and overcoat. The goal of the project is to improve the capability and minimize invasiveness of retinal prostheses, which can restore sight to those suffering from various forms of blindness caused by degeneration of photoreceptors in the retina.