Single-chip white light LED device without fluorescent powder and with adjustable color rendering index and preparation method thereof

Abstract

The present invention provides a single-chip white light LED device without fluorescent powder and with an adjustable color rendering index and a preparation method thereof. The device comprises: a substrate; a first epitaxial layer; n SiO2 layers with micro / nano holes in an array arrangement mode and arranged at the upper portion of the first epitaxial layer; n three-dimensional hexagonal trapezoid structures including InGaN / GaN quantum wells and located at the upper portions of the micro / nano holes; and quantum dot areas, each being located between each two three-dimensional hexagonal trapezoid structures. Through combination of luminous sources of quantum wells and quantum dots, the defects caused by fluorescent powder can be avoided, the advantages of combination of the quantum wells and the quantum dots can be fully utilized, and the luminous efficiency is improved. The components of In in the quantum wells are regulated to allow the sides of the obtained three-dimensional hexagonal trapezoid structures to emit blue light, the upper surfaces of the three-dimensional hexagonal trapezoid structures emit green light and / or yellow light being longer than the blue light in wavelength, the ratio of the mixed quantum dots in the gaps is changed, and therefore, the luminous wavelength and the intensity of the single-chip white light LED device without fluorescent powder and with an adjustable color rendering index are regulated, and a high color rendering index performance is achieved.

Description

technical field [0001] The invention relates to the field of semiconductor epitaxy and chip technology, in particular to an adjustable display finger-free single-chip white LED device without phosphor and a preparation method thereof. Background technique [0002] With the development of modern industry, a series of problems such as global energy crisis and air pollution have become increasingly prominent. Light-emitting diode (LED), as a new type of solid-state lighting source, has been highly valued due to its advantages such as small size, high luminous efficiency, low power consumption, and long life. In recent years, the most common way to obtain white light LEDs is to use low-voltage direct current to excite a single-substrate semiconductor chip, and the light emitted by the chip then excites the phosphor powder coated on the chip, so that the phosphor powder emits long wavelengths visible to the human eye. The light, and finally by adjusting the proportion of phospho...

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Problems solved by technology

[0004] Therefore, many researchers have begun to focus on the development of single-chip white LED lighting technology without phosphors, and proposed many new implementation approaches, such as single-chip integrated multi-wavelength emission white light technology (using appropriate epitaxy technology, growing different 3D or 2D structure to prepare multi-wavelength emission LED) has received great attention, but the color rendering index of white light in these technologies is still relatively low, therefore, the color rendering index should be improved to make the color coordinates close to (1 / 3, 1 / 3) is also particularly urgent

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