Tsinghua to control wavelength devices or change lighting properties

Tsinghua University news network recently, the Tsinghua University microelectronics Office of Professor of Tian orders in "Nature Communications" on the "Nature Communications" published online entitled "spectral tunable flexible full graphene based field controlled light-emitting devices" ("A spectrally tunable all-graphene-based flexible field-effect light" The research paper of -emitting device ") has revealed for the first time the luminescent devices which can regulate the wavelength of luminescence by voltage. Unlike the traditional fixed wavelength LED, the luminescence wavelength of the new device (in a single device) can be continuously adjustable between 750nm and 450nm, breaking through the color synthesis method of existing display devices, and it is expected to have a revolutionary influence on contemporary display, lighting and communication technology. Tian He, a PhD graduate of the Yale University's postdoctoral Wang Xiaomu and the Tsinghua University, is the co - author of the article.

A spectrogram that regulates the wavelength of luminescence through a gate voltage

To date, in all LED devices, the luminescent colors / wavelengths are determined by the luminescent materials. For the existing LED, once the device is completed, the luminous wavelength is fixed. Traditional display or lighting technology can achieve color representation or white light synthesis by adjusting the luminance of several fixed colors (typical devices use red, green, and blue three base colors). The wavelength / color adjustable LED, which is first reported in the article, can greatly reduce the number of luminescent units in the display, thus greatly optimizing the driving circuit and reducing the power consumption. This achievement has far-reaching significance in the related fields. The reviewers of the paper said, "this work is expected to develop new research directions in the field of light emitting devices", "this work is exciting and influential."

A mechanism diagram that regulates the wavelength of luminescence through the grid voltage

Graphene material, with its unique physical properties, is widely used in the subject of controllable photon / optoelectronic devices. However, due to its high zero band gap and high non luminescent recombination, graphene based luminescent devices are a difficult problem and a long-term gap in the academic field. As an innovative method of laser direct writing, the Professor Ren order group obtained a semi reductive srGO material at the interface of graphene oxide and reduced graphene. The material is also characterized by high conductivity of graphene and wide band gap of graphene oxide. By constructing an in-plane gate structure, the Fermi level of srGO can be modulated by the voltage applied to the gate, thus regulating the central wavelength of the luminescence of the graphene LED in real time. The LED also has the characteristics of high brightness and can be made into flexible devices, and is an ideal component of modern LED display, lighting and communication technology.

In recent years, he has been devoted to the research of two dimensional electronic devices such as graphene. It pays special attention to new devices that break through traditional devices and lays the foundation for a new generation of microelectronic devices. Many innovative achievements have been obtained in new graphene based memory, acoustic devices and sensor parts, such as soften. Transparent graphene headphones and low power graphene resistive memory. The research results have been supported by key national natural fund projects.