A photovoltaic device is presented. The photovoltaic device includes a layer stack; and an absorber layer is disposed on the layer stack. The absorber layer comprises selenium, wherein an atomic concentration of selenium varies across a thickness of the absorber layer. The photovoltaic device is substantially free of a cadmium sulfide layer.

The present disclosure describes an embodiment of a thin film transistor based light sensor circuit. The thin film transistor based light sensor circuit includes two thin film transistors, in which a channel region of one of the thin film transistors includes a light sensing area and a channel region of the other thin film transistor has a capping material disposed thereon. The thin film transistor based light sensor circuit further includes a comparator device electrically coupled to the two thin film transistors and configured to detect a current difference between the thin film transistors in response to the thin film transistor with the channel region having the light sensing area being exposed to light.

The present disclosure describes an embodiment of a thin film transistor based light sensor circuit. The thin film transistor based light sensor circuit includes two thin film transistors, in which a channel region of one of the thin film transistors includes a light sensing area and a channel region of the other thin film transistor has a capping material disposed thereon. The thin film transistor based light sensor circuit further includes a comparator device electrically coupled to the two thin film transistors and configured to detect a current difference between the thin film transistors in response to the thin film transistor with the channel region having the light sensing area being exposed to light.

Photovoltaic devices having transparent contact layers are described herein.

Some embodiments include an imaging system comprising a detector substrate, at least one detector circuit comprising a capacitor coupled with the detector substrate, the capacitor arranged to collect an electrical charge from the detector substrate, and the imaging system further comprises at least one programmable current source, arranged to provide a neutralizing charge to the capacitor, and the imaging system is configured to select a value for the neutralizing charge in dependence of a frame number.

Some embodiments include an imaging system comprising a detector substrate, at least one detector circuit comprising a capacitor coupled with the detector substrate, the capacitor arranged to collect an electrical charge from the detector substrate, and the imaging system further comprises at least one programmable current source, arranged to provide a neutralizing charge to the capacitor, and the imaging system is configured to select a value for the neutralizing charge in dependence of a frame number.

A quantum dot includes: a core including a first semiconductor nanocrystal, and a shell disposed on the core, the shell including a second semiconductor nanocrystal and a dopant, wherein the first semiconductor nanocrystal includes a Group III-V compound, the second semiconductor nanocrystal includes zinc (Zn), sulfur (S), and selenium, and the dopant includes lithium, a Group 2A metal having an effective ionic radius less than an effective ionic radius of Zn.sup.2+, a Group 3A element having an effective ionic radius less than an effective ionic radius of Zn.sup.2+, or a combination thereof. Also a method of producing the quantum dot, and a composite, and an electronic device including the quantum dot.