Light-emitting transistor: Light emission from InGaP/GaAs heterojunction bipolar transistors

Abstract

This letter reports the direct observation of the radiative recombination in the graded base layer of InGaP/GaAs heterojunction bipolar transistors (HBTs). For a 1 μm×16 μm emitter HBT, we demonstrate the change of the spontaneous light emission intensity (ΔIout) as the base current (Δib) of the HBT is varied from 0 to 5 mA, i.e., an HBT operating as a light-emitting transistor. We also demonstrate output light modulation from the base layer at 1 MHz with the base current modulated at 1 MHz in normal transistor mode operation of the HBT.

Quantum Well Saturation Effect on the Reduction of Base Transit Time in Light-Emitting Transistors

“…The minority carrier diffusion process in the base region includes three different approaches: 1) the electrons diffuse through the base region without being captured by any QW; 2) the electrons experience the capture and escape processes one time during the diffusion; and 3) the electrons experience the capture and escape processes two times during the diffusion. To obtain reasonable C 0 , τ cap of 6.1 ps is chosen in (1). As a result, the calculation can fit well with our experimental base transit time under thermionic emission model, which is shown in Fig.…”

“…1, the carrier transport mechanism can be divided into three parts: 1) carriers diffuse through QWs; 2) carriers are captured by QWs; and 3) carriers escape from QWs. These mechanisms are coupled to each other and contribute to an effective τ t , as expressed in (1). In this paper, we use (5) to estimate the QW capture time, τ cap , in the LET…”

“…T HE light-emitting transistor (LET) invented by Feng and Holonyak has become one of the promising candidates of next generation high-speed short-range optical data communication light sources because of its extremely fast spontaneous carrier recombination lifetime, τ B , (approximately tens of picosecond) and the inherent three-terminal characteristics of transistors [1]- [4]. As a transistor, an LET can readily produce an additional reference optical signal modulated in-phase with the base current with multi-GHz spontaneous optical bandwidth, which is not easily achieved in conventional lightemitting diodes (LEDs) [5].…”

Photon-assisted breakdown, negative resistance, and switching in a quantum-well transistor laser

“…At the high current density of the high-speed direct-gap HBT, and thus a high enough base current to be interesting ͑even with ␤ ϳ 100͒, we expect significant recombination radiation. 3,4 In fact, employing quantum wells ͑QWs͒ and cavity reflection, 4 we can reinvent the base region and its mechanics ͑its carrier recombination and transport fraction͒, reduce the ␤ gain ͑from ϳ100 to ϳ10͒, and achieve stimulated recombination, i.e., realize a transistor laser. 5,6 The result is a unique transistor in form and operation, as well as a unique three-terminal laser.…”

Ambipolar charge transport and electroluminescence properties of ZnO nanorods

“…Light-emitting transistor that combines optical and electrical functionalities in a single device has a wide range of applications in integrated circuits as well as in signal processing. 13 In this letter, we report the ambipolar charge transport and electroluminescence ͑EL͒ properties of FETs using ZnO nanorods as active materials.…”