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

Photoelectrochemical (PEC) devices are the most similar artificial devices to the nervous system, which is expected to solve the problem of complex computer/nervous system interface (solid-liquid interface) and multifunctional integration (photoelectric fusion) required in the post-Moore era. Based on the different photocurrent ambipolar behavior and different deep ultraviolet solar-blind spectral photoresponse characteristics of α-Ga2O3 and ß-Ga2O3, we designed and constructed the Ga2O3 porous nanostructure PEC device with an adjustable photocurrent bipolar behavior through constructing an α/ß phase junction core-shell structure by adjusting the thickness and the surface state of the shell layer. The switching point of the α/ß-Ga2O3 ambipolar photocurrent shifts toward negative values with the increase of ß-Ga2O3 shell layer thicknesses, and adjustable Boolean logic gates are prepared using the voltage as the input source with a high accuracy manipulated by solar-blind deep ultraviolet light. The controllable solar-blind logic gates based on the ambipolar photocurrent behavior of α/ß-Ga2O3 presented in this study offer a new path for the photoelectric device multifunctional integration needed in the post-Moore era, which can be used in the creation of Ga2O3 half adders and full adders, as well as in the construction of four-input OR gates.

Risk assessment of polychlorinated biphenyls and heavy metals in soils of an abandoned e-waste site in China.

Risk assessment of abandoned e-waste recycling areas received little attention. Herein, we report the concentrations of 16 PCBs and 7 heavy metals in soils near an abandoned e-waste recycling plant in Taizhou, China. Our data showed that levels of tri-, tetra-, penta-, hexa-PCBs were 9.01, 5.56, 12.93, 3.13 mg/kg, and Pb, Cd, Cu were 6082.9, 42.3, 2364.2 mg/kg soil. Cd was the most prevalent contaminant with Nemerow index value of 44.3. Contaminants have been transported from the abandoned site to nearby areas. The ecology risk assessment based on the high toxicological effect in Chinese hamster ovary cells and earthworms showed that both PCBs and heavy metal residue pose high risk to the ecosystem. Hazard quotient showed that Pb, Cd, Hg and Cu pose high health risks for adults and children. Our results recommended a full examination of the risk and regulatory compliance of abandoned e-waste recycling areas in the future.