| AVS 60th International Symposium and Exhibition | |
| Electronic Materials and Processing | Wednesday Sessions |
| Session EM+PS-WeM |
| Session: | Oxides and Dielectrics for Novel Devices and Ultra-dense Memory II |
| Presenter: | Y. Kuo, Texas A&M University |
| Authors: | Y. Kuo, Texas A&M University C.-C. Lin, Texas A&M University |
| Correspondent: | Click to Email |
Currently, light emitting devices (LEDs) are made of inorganic or organic semiconductor materials prepared in crystalline thin films or nanocrystalline dots. They usually emit narrow band light due to the limit of the band gap energy of the semiconductor material. Commercial p-n junction or quantum well LEDs are fabricated with the MOCVD process involving toxic chemicals on the expensive single crystal substrate. Compared with the incandescent or the fluorescent light bulb, these LEDs have many advantages, such as the compact size, long lifetime, and low power consumption, but at the expense of the higher price, e.g., by more than one order of magnitude. On the other hand, the good-quality white light cannot be emitted from a single LED chip. It requires a set of three different LEDs or one LED in combination with a phosphor layer.
Recently, it has been reported that the broad band white light could be emitted from a new type of LED that has a MOS structure with a very thin amorphous metal oxide high-k dielectric layer (1,2,3). The complete device can be easily fabricated on the Si wafer using the IC compatible process at a low thermal budget. In this talk, authors will discuss 1) the light emission mechanism, which is from the thermal excitation of the conductive paths formed during the dielectric breakdown, 2) the optical characteristics, which covers the whole visible and part of the IR wavelength range of 400 nm to 1,000nm with a high color rendering index of 95, and 3) the lifetime, which is longer than 1,500 hours under the continuous operation at room temperature in the air. The unique physical structure and material properties of the sub 10 nm thick metal oxide layer are responsible for the light emitting phenomenon. Experimental results on this kind of device will be shown and discussed. In summary, this type of LED is applicable to a large range of industry, consumer, medical, etc. products.
(1) Y. Kuo and C.-C. Lin, Appl. Phys. Lett.,102, 031117 (2113).
(2) Y. Kuo and C.-C. Lin, ECSSolid State Lett., 2(8) Q59-Q61 (2013).
(3) Y. Kuo and C.-C. Lin, Solid State Electronics, accepted, August 2013.