Reprogrammable Binary and Ternary Optoelectronic Logic Gates Composed of Nanostructured GaN Photoelectrodes with Bipolar Photoresponse Characteristics

Abstract

The elementary electronic‐logic‐gates, performing basic logic functions using electric signals as input, act as a building block of modern digital circuits. Intriguingly, the optoelectronic‐logic‐gates (OLGs), composed of optical devices, are emerging as a new logic platform which enables faster and large‐capacity data transmission and processing by using photons as input. However, the strict operation principle of classic optical devices, for example, the unidirectional photoresponse of the photodetector, restricts the functional enrichment of OLGs. Herein, reprogrammable OLGs in a photoelectrochemical (PEC)‐environment are reported by employing gallium‐nitride semiconductor p–n nanowires as photoelectrodes where bidirectional photocurrent is achieved, leading to the demonstration of various binary OLGs including “NOT”, “XOR”, and “OR”. Strikingly, thanks to the versatile tunability of PEC‐photoelectrodes, the logic function of these OLGs is switchable by simply adjusting programming inputs including light intensity, bias voltage, electrolyte condition, and the physicochemical properties of the nanowire surface. Most importantly, unique ternary OLGs, for example, ternary “OR” gates, can also be realized based on binary ones by just tuning their applied bias for higher logic complexity applications, without changing the device architecture. Such reprogrammable binary and ternary OLGs could provide a new avenue toward next‐generation logic circuits for fast computing and data‐processing in the future.

Modulation of Bipolar Ultraviolet Current in TiO2 Nanofilms for Switching Logic Devices via Ti Valence State Control

“…The input is designated as “1” if the corresponding light source is activated and illuminates the photoelectrode TiO 2 , and “0” if not. The photocurrent is recognized as the output and is labeled “1” if it exceeds −7.4 μA or falls below −9.1 μA, and designated “0” otherwise. ,, At −0.7 V vs SCE, light irradiation (254 nm, 1800 μW·cm –2 ) leads to negative photocurrent, resulting from electron transfer to the solution followed by its reduction with electron acceptors in NaOH solution. Inversely, illumination with light (365 nm, 1800 μW·cm –2 ) generates a positive photocurrent, which can be attributed to the transfer of electrons to the external circuit structure.…”

Facile Semiconductor p–n Homojunction Nanowires with Strategic p-Type Doping Engineering Combined with Surface Reconstruction for Biosensing Applications

“…Essentially, due to their electrolyte-assisted operating characteristics, the operation principle of PEC-type devices not only follows the conventional carrier generation, separation, and migration processes in semiconductors but also encompasses a unique electrochemical procedure that involves the redox reaction at the semiconductor/electrolyte interface, providing us more freedom to regulate their photoresponse behavior [ 6 , 7 ]. Thus far, the PEC-type devices have unleashed their potential in the fields of underwater optical communication [ 8 ], optoelectronic logic [ 9 ], artificial vision [ 2 ], automatic imaging [ 10 ], energy conversion catalysis [ 11 ], etc. Additionally, the unique electrolyte-assisted operation might also enable PEC-type devices for possible liquid-based biosensing, including glucose detection, DNA detection, and cell detection [ 12 – 14 ].…”

Photocurrent Ambipolar Behavior in Phase Junction of a Ga2O3 Porous Nanostructure for Solar-Blind Light Control Logic Devices

“…However, most of these traditional transistors were silicon-based ones, making further miniaturization and integration challenging, which is a significant drawback in the post-Moore era. Fortunately, recent research indicates that optoelectronic logic devices based on two-dimensional materials , and photoelectrochemical (PEC) devices operating in an electrolyte solution environment can effectively overcome this limitation. The most feasible method to obtain homojunction devices is through local electrostatic doping using a semifloating gate , or split gate. , However, operating homojunction-based logic devices is not straightforward; they require simultaneous optical and electrical signals for proper functioning.…”