A semiconductor structure (100) comprising: a substrate (102), a first layer (106) of Al.sub.XGa.sub.YIn.sub.(1−X−Y)N disposed on the substrate, stacks (107, 109) of several second and third layers (108, 110) alternating against each other, between the substrate and the first layer, a fourth layer (112) of Al.sub.XGa.sub.YIn.sub.(1−X−Y)N, between the stacks, a relaxation layer of AlN disposed between the fourth layer and one of the stacks, and, in each of the stacks: the level of Ga of the second layers increases from one layer to the next in a direction from the substrate to the first layer, the level of Ga of the third layers is constant or decreasing from one layer to the next in said direction, the average mesh parameter of each group of adjacent second and third layers increasing from one group to the next in said direction, the thickness of the second and third layers is less than 5 nm.

A semiconductor structure (100) comprising: a substrate (102), a first layer (106) of Al.sub.XGa.sub.YIn.sub.(1−X−Y)N disposed on the substrate, stacks (107, 109) of several second and third layers (108, 110) alternating against each other, between the substrate and the first layer, a fourth layer (112) of Al.sub.XGa.sub.YIn.sub.(1−X−Y)N, between the stacks, a relaxation layer of AlN disposed between the fourth layer and one of the stacks, and, in each of the stacks: the level of Ga of the second layers increases from one layer to the next in a direction from the substrate to the first layer, the level of Ga of the third layers is constant or decreasing from one layer to the next in said direction, the average mesh parameter of each group of adjacent second and third layers increasing from one group to the next in said direction, the thickness of the second and third layers is less than 5 nm.

A semiconductor light-emitting device comprises an epitaxial structure comprising an main light-extraction surface, a lower surface opposite to the main light-extraction surface, a side surface connecting the main light-extraction surface and the lower surface, a first portion and a second portion between the main light-extraction surface and the first portion, wherein a concentration of a doping material in the second portion is higher than that of the doping material in the first portion and, in a cross-sectional view, the second portion comprises a first width near the main light-extraction surface and second width near the lower surface, and the first width is smaller than the second width.

A semiconductor light-emitting device comprises an epitaxial structure comprising an main light-extraction surface, a lower surface opposite to the main light-extraction surface, a side surface connecting the main light-extraction surface and the lower surface, a first portion and a second portion between the main light-extraction surface and the first portion, wherein a concentration of a doping material in the second portion is higher than that of the doping material in the first portion and, in a cross-sectional view, the second portion comprises a first width near the main light-extraction surface and second width near the lower surface, and the first width is smaller than the second width.

A solid-state device, and use and formation thereof. The device includes a light emitter (102) that emits light with abeam propagation direction and includes an emitter epitaxial layer stack (940); a light routing medium (103) in optical communication with the light emitter; and a light detector (104) in optical communication with the light routing medium, which detects light emitted by the light emitter and includes a detector epitaxial stack (945). The light emitter and detector are monolithically formed on a semiconductor substrate. The emitter and detector epitaxial layer stacks include different pluralities of layers of a single epitaxial layer stack. The beam propagation direction is either in-plane with the single epitaxial layer stack and the light detector detects light out of plane with the single epitaxial layer stack, or out of plane with the single epitaxial layer stack and the light detector detects light in plane with the single epitaxial layer stack.

A light-emitting device includes a semiconductor epitaxial structure that has a first surface and a second surface opposite to the first surface, and that includes a first semiconductor layer, an active layer, and a second semiconductor layer sequentially stacked on one another in such order from the first surface to the second surface. The active layer includes a quantum well structure having multiple periodic units each of which includes a well layer and a barrier layer disposed sequentially in such order. A bandgap of the barrier layer is greater than that of the well layer, and the bandgaps of the barrier layers gradually increase in a direction from the first surface of the semiconductor epitaxial structure to the second surface of the semiconductor epitaxial structure.

A photocurable composition includes quantum dots, quantum dot precursor materials, a chelating agent, one or more monomers, and a photoinitiator. The quantum dots are selected to emit radiation in a first wavelength band in the visible light range in response to absorption of radiation in a second wavelength band in the UV or visible light range. The second wavelength band is different than the first wavelength band. The quantum dot precursor materials include metal atoms or metal ions corresponding to metal components present in the quantum dots. The chelating agent is configured to chelate the quantum dot precursor materials. The photoinitiator initiates polymerization of the one or more monomers in response to absorption of radiation in the second wavelength band.

A photocurable composition includes quantum dots, quantum dot precursor materials, a chelating agent, one or more monomers, and a photoinitiator. The quantum dots are selected to emit radiation in a first wavelength band in the visible light range in response to absorption of radiation in a second wavelength band in the UV or visible light range. The second wavelength band is different than the first wavelength band. The quantum dot precursor materials include metal atoms or metal ions corresponding to metal components present in the quantum dots. The chelating agent is configured to chelate the quantum dot precursor materials. The photoinitiator initiates polymerization of the one or more monomers in response to absorption of radiation in the second wavelength band.

A unit pixel of a microdisplay is disclosed. In the unit pixel, sub-pixels that form blue light, green light, and red light are vertically stacked on a growth substrate. Accordingly, the unit pixel area may be reduced, and pixel transfer processing is facilitated.

A unit pixel of a microdisplay is disclosed. In the unit pixel, sub-pixels that form blue light, green light, and red light are vertically stacked on a growth substrate. Accordingly, the unit pixel area may be reduced, and pixel transfer processing is facilitated.