The high-performance broadband photodetectors have attracted intensive scientific interests due to their potential applications in optoelectronic systems. Despite great achievements in two-dimensional (2D) materials based photodetectors such as graphene and black phosphorus, obvious disadvantages such as low optical absorbance and instability preclude their usage for the broadband photodetectors with the desired performance. An alternative approach is to find promising 2D materials and fabricate heterojunction structures for multifunctional hybrid photodetectors. In this work, 2D WS 2 /Si heterojunction with a type-II band alignment is formed in situ. This heterojunction device produced a high I on /I off ratio over 10, 6 responsivity of 224 mA/W, specific detectivity of 1.5 × 10 12 Jones, high polarization sensitivity, and broadband response up to 3043 nm. Furthermore, a 4 × 4 device array of WS 2 /Si heterojunction device is demonstrated with high stability and reproducibility. These results suggest that the WS 2 /Si type-II heterojunction is an ideal photodetector in broadband detection and integrated optoelectronic system.

The newly discovered Group-10 transition metal dichalcogenides (TMDs) like PtSe 2 have promising applications in high-performance microelectronic and optoelectronic devices due to their high carrier mobilities, widely tunable bandages and ultrastabilities. However, the optoelectronic performance of broadband PtSe 2 photodetectors integrated with silicon remains undiscovered. Here, we report the successful preparation of large-scale, uniform and vertically grown PtSe 2 films by simple selenization method for the design of a PtSe 2 /Si nanowire array heterostructure, which exhibited a very good photoresponsivity of 12.65 A/W, a high specific detectivity of 2.5 × 10 13 Jones at −5 V and fast rise/fall times of 10.1/19.5 μs at 10 kHz without degradation while being capable of responding to high frequencies of up to 120 kHz. Our work has demonstrated the compatibility of PtSe 2 with the existing silicon technology and ultrabroad band detection ranging from deep ultraviolet to optical telecommunication wavelengths, which can largely cover the limitations of silicon detectors. Further investigation of the device revealed pronounced photovoltaic behavior at 0 V, making it capable of operating as a self-powered photodetector. Overall, this representative PtSe 2 /Si nanowire array-based photodetector offers great potential for applications in next-generation optoelectronic and electronic devices.

Group‐10 transition metal dichalcogenides (TMDs) with distinct optical and tunable electrical properties have exhibited great potential for various optoelectronic applications. Herein, a self‐powered photodetector is developed with broadband response ranging from deep ultraviolet to near‐infrared by combining FA1−xCsxPbI3 perovskite with PdSe2 layer, a newly discovered TMDs material. Optoelectronic characterization reveals that the as‐assembled PdSe2/perovskite Schottky junction is sensitive to light illumination ranging from 200 to 1550 nm, with the highest sensitivity centered at ≈800 nm. The device also shows a large on/off ratio of ≈104, a high responsivity (R) of 313 mA W−1, a decent specific detectivity (D*) of ≈1013 Jones, and a rapid response speed of 3.5/4 µs. These figures of merit are comparable with or much better than most of the previously reported perovskite detectors. In addition, the PdSe2/perovskite device exhibits obvious sensitivity to polarized light, with a polarization sensitivity of 6.04. Finally, the PdSe2/perovskite detector can readily record five “P,” “O,” “L,” “Y,” and “U” images sequentially produced by 808 nm. These results suggest that the present PdSe2/perovskite Schottky junction photodetectors may be useful for assembly of optoelectronic system applications in near future.

The research of ultraviolet photodetectors (UV PDs) have been attracting extensive attention, due to their important applications in many areas. In this study, PtSe 2 /GaN heterojunction is in-situ fabricated by synthesis of large-area vertically standing two-dimensional (2D) PtSe 2 film on n-GaN substrate. The PtSe 2 /GaN heterojunction device demonstrates excellent photoresponse properties under illumination by deep UV light of 265 nm at zero bias voltage. Further analysis reveals that a high responsivity of 193 mA•W-1 , an ultrahigh specific detectivity of 3.8 × 10 14 Jones, linear dynamic range of 155 dB and current on/off ratio of ~ 10 8 , as well as fast response speeds of 45/102 μs were obtained at zero bias voltage. Moreover, this device response quickly to the pulse laser of 266 nm with a rise time of 172 ns. Such high-performance PtSe 2 /GaN heterojunction UV PD demonstrated in this work is far superior to previously reported results, suggesting that it has great potential for deep UV detection.

He is currently focusing on the development of high temperature lubricants from 'soft' ceramic nanoparticles such as layered metal oxides and organosilica networks.catalysis [26] and energy storage. [27] The most widely investigated classes of exfoliated oxide nanosheets are titanates, [28] niobates [29] and titanoniobates, but various other compositions are now also known, as described in more detail below. Table 1. State of the art metal oxide nanosheet compounds. Compound name Exfoliation method Energy application(s) Remarks Ti 0.87 O 2 0.52-Acid-base by TBAOH [19b,32d] Thin film supercapacitors, [49] batteries, [50] piezos, [51] photocatalysis [52] Lateral size up to 100 μm [32d] Fe 0.8 Ti 1.2 O 4 0.8-Acid-base by TBAOH [41d] Photocatalysis [53] Ni 0.4 Ti 1.6 O 4 0.8-Acid-base by TBAOH Photocatalysis [53] Ti 0.91 O 2 0.36−Acid-base by TBAOH [18,54] Photovoltaics, [55] batteries, [56] fuel cells, [57] acid catalysis, [58] photocatalysis [59] Ti 4 O 9 2-Acid-base by TBAOH [37] Batteries, [37,60] fuel cells, [61] photocatalysis [59a,62] MnO 2 0.4-Acid-base by TBAOH [35] Supercapacitors, [35,63] Photovoltaics, [64] batteries, [65] photocatalysis [59a] Mn 1-x Ru x O 2 (x = 0.05 and 0.1) Acid-base by TBAOH [42] Supercapacitors [42] RuO 2 0.2-Acid-base by TBAOH [66] Supercapacitors, [67] fuel cells [68] Ca 2 Nb 3 O 10 − Acid-base by TBAOH [69] Ca 2 Nb 3 O 10−x N y -Acid-base by TBAOH [74] Photocatalysis [74] Ca 2 Na n−3 Nb n O 3n+1 − (n = 4, 5, 6) Acid-base by TBAOH [71] Ca 2-x Sr x Nb 3 O 10 -(x = 0, 0.5, 1, 1.5, 2) Acid-base by TBAOH [75] Photocatalysis [75] Ca 2 Nb 3-x Ta x O 10 -(x = 0.3, 1, 1.5) Acid-base by TBAOH [75] Photocatalysis [75] Ca 2 Nb 3-x Rh x O 10−δ -Acid-base by TBAOH [76] Photocatalysis [76] SrNb 2 O 6 F − Acid-base by TBAOH [69] (Eu 0.56 Ta 2 O 7 ) 2-Acid-base by TBAOH [77] TaO 3 -Acid-base by TBAOH [38] Batteries, [56b] photocatalysis [78] Sr 1.5 Ta 3 O 10 2-Acid-base by TBAOH [79] CaNaTa 3 O 10 2-Acid-base by TBAOH [20] Ca 2 Ta 3 O 10-x N y -Acid-base by TBAOH [44] Photocatalysis [44] Sr 2−x Ba x Ta 3 O 10-y N z -(x = 0.0, 0.5, 1.0) Acid-base by TBAOH [80] Photocatalysis [80] SrLaTi 2 TaO 10 2-Acid-base by TBAOH [20] Ca 2 Ta 2 TiO 10 2-Acid-base by TBAOH [20] Ti (5.2-2x)/6 Mn x/2 O 2 (x = 0.1, 0.2, 0.3, 0.4) Acid-base by TBAOH [81] Ti 1−x−y Fe x Co y O 2 (0 ≤ x ≤ 0.4 and 0 ≤ y ≤ 0.2) Acid-base by TBAOH [82] Cs 4 W 11 O 36 2-Acid-base by TBAOH [83] (MWO 6 ) -(M = Nb, Ta) Acid-base by TBAOH [45] Acid catalysis, [84] photocatalysis [85] NbMoO 6 -Acid-base by TBAOH [86] Acid catalysis [86,87] W 2 O 7 2-Acid-base by TMAOH [45] Photocatalysis [88] (Ti 1.825-x Nb x O 4 ) 0.7-(x = 0-0.03) Acid-base by TBAOH [89] (Ti 1.65 Mg 0.35 O 4 ) 0.7-Acid-base by TBAOH [90] Attempt to make (Ti 1.65 Ni 0.35 O 4 ) 0.7failed [91]Nb 3 O 8 -Acid-base by TBAOH [92] Acid catalysis, [92] photocatalysis [36,93] Nb 6 O 17 4-Acid-base by TBAOH [94] and intercalation of n-propylamine [95] Photovoltaics, [96] photocatalysis [59a][73c,97] TiNbO 5 − Acid-base by TBAOH [71] Batteries, [71] photovoltaics, [71] b...

Purpose. We compared the clinical value of 16a-18F-fluoro-17b-estradiol ( 18 F-FES) positron emission tomography (PET)/ computed tomography (CT) and 18 F-fluoro-2-deoxy-D-glucose ( 18 F-FDG) PET/CT and investigated whether and how 18 F-FES PET/CT affects the implemented management of newly diagnosed estrogen receptor positive breast cancer patients. Materials and Methods. We retrospectively analyzed 19 female patients newly diagnosed with immunohistochemistry-confirmed estrogen receptor (ER)-positive breast cancer who underwent 18 F-FES and 18 F-FDG PET/CT within 1 week in our center. The sensitivity of 18 F-FES and 18 F-FDG in diagnosed lesions were compared. To investigate the definite clinical impact of 18 F-FES on managing patients with newly diagnosed ER positive breast cancer, we designed two kinds of questionnaires. Referring physicians completed the first questionnaire based on the 18 F-FDG report to propose the treatment regime, and the second was completed immediately after reviewing the imaging report of 18 F-FES to indicate intended management changes. Results. In total, 238 lesions were analyzed in 19 patients with newly diagnosed ER-positive breast cancer. Lesion detection was achieved in 216 sites with 18 F-FES PET and in 197 sites with 18 F-FDG PET/CT. These results corresponded to sensitivities of 90.8% for 18 F-FES versus 82.8% for 18 F-FDG PET/CT in diagnosed lesions. Thirty-five physicians were given the questionnaires referring to the treatment strategy, with 27 of them completing both questionnaires. The application of 18 F-FES in addition to 18 F-FDG PET/CT changed the management in 26.3% of the 19 patients with newly diagnosed ER-positive breast cancer. Conclusion. Performing 18 F-FES PET/CT in newly diagnosed ER-positive breast cancer patients increases the value of diagnosis equivocal lesions and treatment management compared with 18 F-FDG PET/CT. The Oncologist 2019;24:e1277-e1285 Implications for Practice: This study investigated whether 16a-18F-fluoro-17b-estradiol ( 18 F-FES) positron emission tomography (PET)/computed tomography (CT) affects the clinical management of patients with newly diagnosed estrogen receptor (ER)-positive breast cancer. Physicians completing two questionnaires comparing the clinical impact of 18F-FES and 18F-FDG on individual management plans in patients with newly diagnosed ER-positive breast cancer confirmed that 18F-FES scans led to change in management in 26.3% of the 19 patients with newly diagnosed ER positive breast cancer. This retrospective study indicates the potential impact of 18F-FES PET/CT on intended management of patients with newly diagnosed estrogen receptor positive breast cancer in comparison to 18F-fluoro-2-deoxy-D-glucose PET/CT.

Flexible and sensitive sensors that can detect external stimuli such as pressure, temperature, and strain are essential components for applications in health diagnosis and artificial intelligence. Multifunctional sensors with the capabilities of sensing pressure and temperature simultaneously are highly desirable for health monitoring. Here, we have successfully fabricated a flexible and simply structured bimodal sensor based on metal-organic frameworks (MOFs) derived porous carbon (PC) and polydimethylsiloxane (PDMS) composite. Attributed to the porous structure of PC/PDMS composite, the fabricated sensor exhibits high sensitivity (15.63 kPa), fast response time (<65 ms), and high durability (∼2000 cycles) for pressure sensing. Additionally, its application in detecting human motions such as subtle wrist pulses in real time has been demonstrated. Furthermore, the as-prepared device based on the PC/PDMS composite exhibits a good sensitivity (>0.11 °C) and fast response time (∼100 ms), indicating its potential application in sensing temperature. All of these capabilities indicate its great potential in the applications of health monitoring and artificial skin for artificial intelligence system.

The exfoliation and deposition of large (10-100 μm) Ti0.87O2 and small (0.1-1 μm) Ti0.91O2 nanosheets from lepidocrocite-type protonated titanates was investigated for getting high quality films. Exfoliation was carried out with different tetra-alkyl ammonium ions (TAA(+)) and varying TAA(+)/H(+) ratios, and the colloidal solutions were characterized by small-angle X-ray scattering (SAXS) and ultraviolet-visible (UV-vis) spectroscopy. Using Langmuir-Blodgett deposition the titanate nanosheets were directly transferred onto a Si substrate. The resulting films were characterized by atomic force microscopy (AFM).The results indicate that the H1.07Ti1.73O4 titanate exfoliated at very low ratios of TAA(+)/H(+); no lower threshold for exfoliation was observed for the TAA(+) concentration. Nanosheets exfoliated at very low ratios of TAA(+)/H(+) typically showed a small size and porous surface. Subsequent exfoliation of the remaining layered titanate particles yielded much higher quality nanosheets. The optimized deposition parameters for Langmuir-Blodgett films suggest that the surface pressure is a key parameter to control the coverage of the film. The bulk concentration of nanosheets was found to be a less important deposition parameter in the LB deposition process. It only influenced whether the desired surface pressure could be reached at a given maximum degree of compression.