Abstract: A semiconductor structure includes a first channel layer and a first barrier layer on the first channel layer. The first channel layer has a first potential well adjacent to the interface between the first channel layer and the first barrier layer. The semiconductor structure further includes a second channel layer on the first barrier layer, a second barrier layer on the second channel layer, and an intermediate layer between the second channel layer and the second barrier layer. The second channel layer has a second potential well adjacent to the interface between the second channel layer and the intermediate layer. The intermediate layer has a greater energy gap than either the first barrier layer or the second barrier layer. The energy gap of the first barrier layer is no less than the energy gap of the second barrier layer.

Abstract: A semiconductor device includes a semiconductor stack, an insulating structure, an electrode structure, and a protective layer. The insulating structure is disposed on the semiconductor stack and includes a first portion. The first portion includes a first opening exposing an inner sidewall of the insulating structure. The electrode structure includes a metal material. The protective layer is disposed between the inner sidewall and the electrode structure, and includes a second opening. The electrode structure is disposed in the first opening and in contact with the protective layer, and the electrode structure is electrically connected to the semiconductor stack through the second opening. The insulating structure includes a first material, and the protective layer includes a second material.

Abstract: A semiconductor device includes a substrate, a semiconductor stack, an insulating structure, and an electrode. The semiconductor stack is disposed on the substrate and includes a two-dimensional electron gas region. The insulating structure is disposed on the semiconductor stack and includes a first insulating layer and a second insulating layer. The first insulating layer includes a first opening exposing the first inner sidewall of the first insulating layer. The second insulating layer is disposed on the first insulating layer and covers the first inner sidewall of the first insulating layer. The second insulating layer includes a second opening disposed in the first opening and exposing the second inner sidewall of the second insulating layer. The second insulating layer includes a step profile, and a step edge of the step profile coincides with the second inner sidewall. The electrode is disposed on the insulating structure and in the second opening.

Abstract: A light-emitting device is provided. The light-emitting device includes a control part, a light-emitting part, a first electrode, and a second electrode. The control part includes a first semiconductor stack having a two-dimensional gas therein. The light-emitting part includes a second semiconductor stack. The first electrode electrically connects the control part and the light-emitting part. The second electrode electrically connects the control part and the light-emitting part. The control part and the light-emitting part are electrically connected in parallel through the first electrode and the second electrode.

Abstract: A voltage converter circuit, comprising: a bridge rectifier; a first transistor, having a first end, a second end and a third end; a second transistor, having a first end and a second end; wherein the first end of the first transistor and the first end of second transistor are electrically connected to bridge rectifier, and the second end of the first transistor is electrically connected to the first end of the second transistor; and a Zener diode, connected between the third end of the first transistor and the second end of the second transistor.

Abstract: A voltage converter circuit, comprising: a bridge rectifier; a first transistor, having a first end, a second end and a third end; a second transistor, having a first end and a second end; wherein the first end of the first transistor and the first end of second transistor are electrically connected to bridge rectifier, and the second end of the first transistor is electrically connected to the first end of the second transistor; and a Zener diode, connected between the third end of the first transistor and the second end of the second transistor.