Tunneling between density-of-state tails: Theory and effect on Esaki diodes

Abstract

Tunneling between density-of-state tails: Theory and effect on Esaki diodes

Theoretical Prediction of Semiconductor-Free Negative Differential Resistance Tunnel Diodes with High Peak-to-Valley Current Ratios Based on Two-Dimensional Cold Metals

“…However, those two-terminal NDR diodes have two primary features hindering their applications: (i) The peak-to-valley current ratio (PVCR) is rather low in tunnel diodes that are compatible with CMOS technology. − In these diodes, the PVCR is usually less than 10, not high enough for memory applications (tunnel SRAM). (ii) The III–V semiconductors that produce high PVCR values (between 5 and 144) are not compatible with the current CMOS technology. , The low PVCR values in two-terminal NDR tunnel diodes have been attributed to the band-tail tunneling, which originates from the strong doping and doping fluctuations and has been studied in detail by many authors using different approaches. − Many research contributions have been reported to improve the PVCR value over 100 based on a CMOS-compatible process. Extremely high, by 2–3 orders of magnitude, PVCR values have been obtained in NDR circuits based on a combination of a Si-based CMOS and a SiGe heterojunction bipolar transistor. − Despite their high PVCR values, such devices possess complex circuit topology with at least three (four) transistors for a Λ-type (N-type) NDR effect (Figure ), which makes them unsuitable for memory applications …”

Full quantum simulation of Shockley–Read–Hall recombination in p-i-n and tunnel diodes

“…Detrapping of these charged states at a later time is the cause of secondary pulses in the current waveform (after pulsing) that are erroneously interpreted as photon counts [1,3]. On the other hand, in Esaki diodes, recombination induced by defect states is one of the main contributors to the degradation of the peak-to-valley current ratio in the forward bias regime [4,5].…”

Mechanism of extraordinary gate-length dependence of quantum dot operation in isoelectronic-trap-assisted tunnel FETs

“…The previous reports clarified the effect of tunneling via traps on the current characteristics of a TFET or Esaki diode using a similar method. 21,22) These reports discussed the tunneling via traps, which form the tail states near the band-edge. This study aims to construct a tunneling transport model based on a relatively simple method compared with those used in previous works and clarify why the Coulomb blockade is observed experimentally only in short-channel TFETs.…”