The LED pixel includes a driver IC (20) and an LED chip (40); the LED chip (40) is stacked and mounted on a surface of the driver IC (20), and a wire (31) going from the cathode of the LED chip (40) is connected to the driver IC (20). The driver IC (20) is an unpackaged die. An insulation layer is disposed on the surface of the die, and a pad (30) disposed on the insulation layer is connected to a positive electrode. The LED chip (40) is mounted on the pad (30), and the anode of the LED chip (40) is electrically connected with the pad (40). This improves the light transmittance of the LED display product.

The LED pixel includes a driver IC (20) and an LED chip (40); the LED chip (40) is stacked and mounted on a surface of the driver IC (20), and a wire (31) going from the cathode of the LED chip (40) is connected to the driver IC (20). The driver IC (20) is an unpackaged die. An insulation layer is disposed on the surface of the die, and a pad (30) disposed on the insulation layer is connected to a positive electrode. The LED chip (40) is mounted on the pad (30), and the anode of the LED chip (40) is electrically connected with the pad (40). This improves the light transmittance of the LED display product.

Embodiments relate to functional test methods useful for fabricating products containing Light Emitting Diode (LED) structures. In particular, LED arrays are functionally tested by injecting current via a displacement current coupling device using a field plate comprising of an electrode and insulator placed in close proximity to the LED array. A controlled voltage waveform is then applied to the field plate electrode to excite the LED devices in parallel for high-throughput. A camera records the individual light emission resulting from the electrical excitation to yield a function test of a plurality of LED devices. Changing the voltage conditions can excite the LEDs at differing current density levels to functionally measure external quantum efficiency and other important device functional parameters.

Embodiments relate to functional test methods useful for fabricating products containing Light Emitting Diode (LED) structures. In particular, LED arrays are functionally tested by injecting current via a displacement current coupling device using a field plate comprising of an electrode and insulator placed in close proximity to the LED array. A controlled voltage waveform is then applied to the field plate electrode to excite the LED devices in parallel for high-throughput. A camera records the individual light emission resulting from the electrical excitation to yield a function test of a plurality of LED devices. Changing the voltage conditions can excite the LEDs at differing current density levels to functionally measure external quantum efficiency and other important device functional parameters.

An ultraviolet light emitting device is disclosed. An ultraviolet light emitting device according to a first embodiment of the disclosed technology comprises: a substrate having a first surface and a second surface facing the first surface; and a light emitting diode comprising a first type semiconductor layer, an active layer which emits ultraviolet light, and a second type semiconductor layer, the light emitting diode being formed on the first surface of the substrate, wherein the surface area of the substrate divided by the light emitting area of the light emitting diode may be 6.5.

The surface of a light emitting device is roughened to enhance the light extraction efficiency of the surface, but the amount of roughened area is selected to achieve a desired level of light extraction efficiency. Photo-lithographic techniques may be used to create a mask that limits the roughening to select areas of the light emitting surface. Because the amount of roughened area can be precisely controlled, the light extraction efficiency can be precisely controlled, substantially independent of the particular process used to roughen the surface. Additionally, the selective roughening of the surface may be used to achieve a desired light emission output pattern.

The surface of a light emitting device is roughened to enhance the light extraction efficiency of the surface, but the amount of roughened area is selected to achieve a desired level of light extraction efficiency. Photo-lithographic techniques may be used to create a mask that limits the roughening to select areas of the light emitting surface. Because the amount of roughened area can be precisely controlled, the light extraction efficiency can be precisely controlled, substantially independent of the particular process used to roughen the surface. Additionally, the selective roughening of the surface may be used to achieve a desired light emission output pattern.

A semiconductor light emitting device includes a light emitting structure in which a first conductive semiconductor layer, an active layer, and a second conductive semiconductor layer are sequentially laminated, an insulating layer disposed on the light emitting structure and including first and second openings, an electrode layer disposed on the insulating layer and including first and second electrodes, and an adhesive layer disposed between the electrode layer and the insulating layer and including first and second openings. The first opening of the adhesive layer overlaps the first opening of the insulating layer and is equal to or larger than the first opening of the insulating layer. The second opening of the adhesive layer overlaps the second opening of the insulating layer and is equal to or larger than the second opening of the insulating layer.

A method of making an inorganic semiconductor structure suitable for micro-transfer printing includes providing a growth substrate and forming one or more semiconductor layers on the growth substrate. A patterned release layer is formed on the conductor layer(s) and bonded to a handle substrate. The growth substrate is removed and the semiconductor layer(s) patterned to form a semiconductor mesa. A dielectric layer is formed and then patterned to expose first and second contacts and an entry portion of the release layer. A conductor layer is formed on the dielectric layer, the first contact, and the second contact and patterned to form a first conductor in electrical contact with the first contact and a second conductor in electrical contact with the second contact but electrically separate from the first conductor. At least a portion of the release layer is removed.

A method of making an inorganic semiconductor structure suitable for micro-transfer printing includes providing a growth substrate and forming one or more semiconductor layers on the growth substrate. A patterned release layer is formed on the conductor layer(s) and bonded to a handle substrate. The growth substrate is removed and the semiconductor layer(s) patterned to form a semiconductor mesa. A dielectric layer is formed and then patterned to expose first and second contacts and an entry portion of the release layer. A conductor layer is formed on the dielectric layer, the first contact, and the second contact and patterned to form a first conductor in electrical contact with the first contact and a second conductor in electrical contact with the second contact but electrically separate from the first conductor. At least a portion of the release layer is removed.