Device response principles and the impact on energy resolution of epitaxial quantum dot scintillators with monolithic photodetector integration.

Epitaxial quantum dot (QD) scintillator crystals with picosecond-scale timing and high light yield have been created for medical imaging, high energy physics and national security applications. Monolithic photodetector (PD) integration enables the sensing of photons generated within the waveguiding crystal and allows a wide range of scintillator-photodetector coupling geometries. Until recently, these doubly novel devices have suffered from complex, high variance responses to monoenergetic sources which significantly reduces their precision and accuracy.

Bias-Tunable Quantum Well Infrared Photodetector.

With the rapid advancement of Artificial Intelligence-driven object recognition, the development of cognitive tunable imaging sensors has become a critically important field. In this paper, we demonstrate an infrared (IR) sensor with spectral tunability controlled by the applied bias between the long-wave and mid-wave IR spectral regions. The sensor is a Quantum Well Infrared Photodetector (QWIP) containing asymmetrically doped double QWs where the external electric field alters the electron population in the wells and hence spectral responsivity.

InGaAs Inversion Layer Mobility and Interface Trap Density from Gated Hall Measurements.

In this work, we use gated Hall method for direct measurement of free carrier density and electron mobility in inversion InGaAs MOSFET channels. At room temperature, the highest Hall mobility of 1800 cm/Vs is observed at electron density in the channel ≈1×10 cm. A comparison with mobility values estimated from transistor characteristics reveals a significant underestimation of mobility which arises from overestimation of channel density obtained from C-V measurements.

Complete voltage recovery in quantum dot solar cells due to suppression of electron capture.

Extensive investigations in recent years have shown that addition of quantum dots (QDs) to a single-junction solar cell decreases the open circuit voltage, VOC, with respect to the reference cell without QDs. Despite numerous efforts, the complete voltage recovery in QD cells has been demonstrated only at low temperatures. To minimize the VOC reduction, we propose and investigate a new approach that combines nanoscale engineering of the band structure and the potential profile.