Manufacturing method for flexible device, flexible device, solar cell, and light emitting device
View Patent ↗Provided are a method of manufacturing a flexible device and the flexible device, a solar cell, and a light emitting device. The method of manufacturing a flexible device includes providing a device layer on a sacrificial substrate, contacting a flexible substrate on one side surface of the device layer, and removing the sacrificial substrate. A large area device may be transferred onto the flexible substrate with superior alignment to realize and manufacture the flexible device. In addition, since mass production is possible, the economic feasibility may be superior. Also, when a large area solar cell having a thin thickness is manufactured, since a limitation such as twisting of a thin film of a solar cell may be effectively solved, the economic feasibility and stability may be superior.
1. A method of manufacturing a light emitting device pixel display, the method comprising:
forming a light emitting device layer on an upper surface of a silicon substrate, wherein the device layer includes:
an AIN buffer layer directly contacting the upper surface of the silicon substrate,
an n-GaN layer stacked on the AIN buffer layer,
an InGaN layer stacked on the n-GaN layer, and
a p-GaN layer stacked on the InGaN layer;
patterning the p-GaN layer, the InGaN layer, the n-GaN layer, and the AIN buffer layer to form a plurality of pixels separated from each other and to expose a portion of the upper surface of the silicon substrate between the plurality of pixels, each pixel including the AIN buffer layer, the n-GaN layer, the InGaN layer, and the p-GaN layer;
adhering the p-GaN layer of each pixel to a first flexible substrate without a separate adhesion layer, the first flexible substrate including polydimethylsiloxane (PDMS) having adhesion and flexibility in itself;
wet-etching the exposed portion of the upper surface of the silicon substrate and a lower surface of the silicon substrate to remove the silicon substrate from the AIN buffer layer of each pixel, each pixel being sustained on the first flexible substrate during removal of the silicon substrate, wherein the silicon substrate is removed through immersion into an etchant, the etchant being a mixture comprising a first component comprising ammonium hydrogen fluoride and ammonium nitrate and a second component comprising dilute sulfuric acid, the first and second components mixed at a ratio of about 1:1 to about 1:2;
forming an adhesion layer on a second flexible substrate, the adhesion layer including epoxy and the second flexible substrate including polyethylene terephthalate (PET);
adhering the AIN buffer layer of each pixel to the adhesion layer on the second flexible substrate, an adhesion force between the epoxy of the adhesion layer and the AIN buffer layer of each pixel is greater than an adhesion force between the PDMS of the first flexible substrate and the p-GaN layer of each pixel; and
upwardly separating the first flexible substrate from the p-GaN layer of each pixel to transfer the plurality of pixels to the second flexible substrate.
2. The method of claim 1 , wherein the silicon substrate is removed in a manner such that all of the silicon substrate contacting the plurality of pixels is removed by the etchant.