Kim Iurii, Kivisaari Pyry, Oksanen Jani, Suihkonen Sami
Department of Electronics and Nanoengineering, Aalto University, P.O. Box 13500, 00076 Aalto, Finland.
Engineered Nanosystems Group, Aalto University, P.O. Box 12200, 00076 Aalto, Finland.
Materials (Basel). 2017 Dec 12;10(12):1421. doi: 10.3390/ma10121421.
Almost all modern inorganic light-emitting diode (LED) designs are based on double heterojunctions (DHJs) whose structure and current injection principle have remained essentially unchanged for decades. Although highly efficient devices based on the DHJ design have been developed and commercialized for energy-efficient general lighting, the conventional DHJ design requires burying the active region (AR) inside a pn-junction. This has hindered the development of emitters utilizing nanostructured ARs located close to device surfaces such as nanowires or surface quantum wells. Modern DHJ III-N LEDs also exhibit resistive losses that arise from the DHJ device geometry. The recently introduced diffusion-driven charge transport (DDCT) emitter design offers a novel way to transport charge carriers to unconventionally placed ARs. In a DDCT device, the AR is located apart from the pn-junction and the charge carriers are injected into the AR by bipolar diffusion. This device design allows the integration of surface ARs to semiconductor LEDs and offers a promising method to reduce resistive losses in high power devices. In this work, we present a review of the recent progress in gallium nitride (GaN) based DDCT devices, and an outlook of potential DDCT has for opto- and microelectronics.
几乎所有现代无机发光二极管（LED）设计都基于双异质结（DHJ），其结构和电流注入原理几十年来基本保持不变。尽管基于DHJ设计的高效器件已被开发并商业化用于节能通用照明，但传统的DHJ设计需要将有源区（AR）埋入pn结内部。这阻碍了利用靠近器件表面的纳米结构有源区（如纳米线或表面量子阱）的发光体的发展。现代DHJ III-N族LED还表现出由DHJ器件几何结构引起的电阻损耗。最近引入的扩散驱动电荷传输（DDCT）发光体设计提供了一种将电荷载流子传输到非常规放置的有源区的新方法。在DDCT器件中，有源区与pn结分开，电荷载流子通过双极扩散注入到有源区。这种器件设计允许将表面有源区集成到半导体LED中，并为降低高功率器件中的电阻损耗提供了一种有前景 的方法。在这项工作中我们对基于氮化镓（GaN）的DDCT器件的最新进展进行了综述，并展望了DDCT在光电子学和微电子学中的潜力。
