Size-Independent Reconfigurable Logic Gate with Bismuth Oxide Based Photoelectrochemical Device

Abstract

XOR gate, an important building block in computational circuits, is often constructed by combining other basic logic gates, and the hybridity inevitably leads to its complexity. A photoelectrochemical device could realize XOR function based on the current change of the photoelectrode; however, such signal is highly sensitive to photoelectrode size and therefore requires precise manufacturing at a high cost. Herein we developed a novel XOR gate based on the light-induced open-circuit potential (OCP) of the Bi2O3 photoelectrode. Surprisingly, the OCP of Bi2O3 does not increase with light intensity according to the traditional logarithmic relationship. Instead, an unusual decrease in OCP is observed at high light intensity, which is attributed to the dramatic light-induced increase in surface states that can be easily regulated by varying the oxygen partial pressure during reactive magnetron sputtering. Based on such a nonmonotonic variation of OCP, a facile Bi2O3-based gate is designed to realize the XOR function. Unlike the commonly used current signal, OCP is size independent, and therefore, the Bi2O3-based gate does not require high manufacturing accuracy. Moreover, in addition to XOR, the Bi2O3-based PEC gate also demonstrates great versatility in realizing other logic functions including AND, OR, NOT, NIH, NAND, and NOR. The strategy of modulating and applying nonmonotonic OCP signal opens a new avenue for designing size-independent reconfigurable logic gates at low manufacturing cost.

A 2.4 V Aqueous Zinc-Ion Battery Enabled by the Photoelectrochemical Effect of a Modified BiOI Photocathode: Shattering the Shackle of the Electrochemical Window of an Aqueous Electrolyte

“…From the high-resolution O 1s XPS spectra of h-BiOI and h/s-BiOI, three fitting peaks at around 529.9, 531.2, and 531.9 eV are recognized, which are corresponding to the lattice oxygen (Bi−O), oxygen vacancy, and absorbed oxygen, respectively (Figure 2f). 34 Of these, the peak assigned to oxygen vacancy is associated with surface trap defects, 35,36 and the peak area ratio of oxygen vacancy of h/s-BiOI (18.27%) is markedly lower than that (44.21%) of h-BiOI. Meanwhile, the peak area ratio of lattice oxygen increases from 34.96% (h-BiOI) to 65.34% (h/s-BiOI), suggesting a decrease in the concentration of oxygen vacancies after surface modification.…”