Abstract: A device includes a P-N junction comprising a monolithic N-type semiconductor layer coupled to a monolithic P-type semiconductor layer. The monolithic N-type semiconductor layer includes a first portion and a second portion. The first portion has a first surface and the second portion has a second surface facing away from the first surface. The monolithic P-type semiconductor layer includes a third portion and a fourth portion. The third portion has a third surface and the fourth portion has a fourth surface facing away from the third surface.

Abstract: Graphene printing is disclosed. A disclosed example graphene printing apparatus includes a gas source to cause a graphene precursor gas to flow across a surface of a substrate, and a localized heat source to locally heat portions of the surface to cause graphene to grow at the portions of the surface based on a printing pattern.

Abstract: An RFID security device for product packaging is disclosed. The security device includes an RFID tag disposed on a first portion of a product package, and a booster antenna disposed on a second portion of the product package. The RFID tag and booster antenna are positioned on the product package so that the RFID tag will be electromagnetically coupled to the booster antenna when the product package is closed, and the RFID tag will be decoupled from the booster antenna when the product package is open.

Abstract: Examples disclosed herein relate to a layered RFID tag. In one implementation, a layered passive chipless RFID tag includes a first conductive layer, a second dielectric layer, and a third conductive layer. The first, second, and third layers may be in a stacked configuration with the second layer between the first layer and the second layer.

Abstract: In some examples, a controllable read blocking based radio-frequency identification (RFID) device may include a substrate layer, and a trace formed of a conductive material and disposed on, partially within, or fully within the substrate layer. The controllable read blocking based RFID device may further include a controllable read blocking layer disposed on the substrate layer and the trace and including a fluid disposed in the controllable read blocking layer to selectively block or allow passage of electromagnetic waves to the trace to respectively inhibit or allow communication of a RFID reading device with the controllable read blocking based RFID device.

Abstract: In some examples, a controllable read blocking based radio-frequency identification (RFID) device may include a substrate layer, and a trace formed of a conductive material and disposed on, partially within, or fully within the substrate layer. The controllable read blocking based RFID device may further include a controllable read blocking layer disposed on the substrate layer and the trace and including a fluid disposed in the controllable read blocking layer to selectively block or allow passage of electromagnetic waves to the trace to respectively inhibit or allow communication of a RFID reading device with the controllable read blocking based RFID device.