Tereshchenko Oleg E, Golyashov Vladimir A, Rusetsky Vadim S, Kustov Danil A, Mironov Andrey V, Demin Alexander Yu
Rzhanov Institute of Semiconductor Physics, Siberian Branch, Russian Academy of Sciences, Novosibirsk 630090, Russia.
Synchrotron Radiation Facility SKIF, Boreskov Institute of Catalysis, Siberian Branch, Russian Academy of Sciences, Kol'tsovo 630559, Russia.
Nanomaterials (Basel). 2023 Jan 19;13(3):422. doi: 10.3390/nano13030422.
Improving the efficiency of spin generation, injection, and detection remains a key challenge for semiconductor spintronics. Electrical injection and optical orientation are two methods of creating spin polarization in semiconductors, which traditionally require specially tailored p-n junctions, tunnel or Schottky barriers. Alternatively, we introduce here a novel concept for spin-polarized electron emission/injection combining the optocoupler principle based on vacuum spin-polarized light-emitting diode (spin VLED) making it possible to measure the free electron beam polarization injected into the III-V heterostructure with quantum wells (QWs) based on the detection of polarized cathodoluminescence (CL). To study the spin-dependent emission/injection, we developed spin VLEDs, which consist of a compact proximity-focused vacuum tube with a spin-polarized electron source (p-GaAs(Cs,O) or NaKSb) and the spin detector (III-V heterostructure), both activated to a negative electron affinity (NEA) state. The coupling between the photon helicity and the spin angular momentum of the electrons in the photoemission and injection/detection processes is realized without using either magnetic material or a magnetic field. Spin-current detection efficiency in spin VLED is found to be 27% at room temperature. The created vacuum spin LED paves the way for optical generation and spin manipulation in the developing vacuum semiconductor spintronics.
提高自旋产生、注入和检测的效率仍然是半导体自旋电子学面临的关键挑战。电注入和光取向是在半导体中产生自旋极化的两种方法，传统上需要专门定制的p-n结、隧道或肖特基势垒。或者，我们在此引入一种用于自旋极化电子发射/注入的新概念，它结合了基于真空自旋极化发光二极管（自旋VLED）的光耦合器原理，使得基于极化阴极发光（CL）检测能够测量注入到具有量子阱（QW）的III-V异质结构中的自由电子束极化。为了研究自旋相关的发射/注入，我们开发了自旋VLED，它由一个紧凑的近贴聚焦真空管组成，带有自旋极化电子源（p-GaAs(Cs,O)或NaKSb）和自旋探测器（III-V异质结构），两者均被激活到负电子亲和势（NEA）状态。在光发射以及注入/检测过程中，无需使用磁性材料或磁场就能实现光子螺旋度与电子自旋角动量之间的耦合。发现自旋VLED在室温下的自旋电流检测效率为27%。所制造的真空自旋LED为正在发展的真空半导体自旋电子学中的光学生成和自旋操控铺平了道路。
