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Eu2+-activated phosphors are widely applied in lighting and display areas because of their good optical performance. In this paper, an excellent green-emitting zeolite-3A: 1.3 wt% Eu phosphor is prepared by a green and eco-friendly high-thermal reaction method without any reducing atmosphere or agents. Meanwhile, the reducing mechanism from Eu3+ ions to Eu2+ ions is investigated. The experiment results show that the morphology, crystal structure, and luminescent property are affected by sintering temperature. The resulting sample shows the broad excitation band is in the range of 310–450 nm and the peak of the broad emission band is located at 523 nm. Furthermore, zeolite-3A: 1.3 wt% Eu phosphor is encapsulated on a commercial UV-emitting chip to fabricate a purity green light-emitting diode (LED) with the Commission Internationale de L’Eclairage (CIE) color coordinates at (0.295, 0.537).

Due to the advantages of narrow energy distribution of plasmonic hot-electrons in Ag and the high density of states in the TiO2 conduction band, an Ag/TiO2 composite is considered to be an ideal combination to construct a plasmonic hot-electron photodetector with high detectivity and a high response speed. In this work, we fabricate a porous Ag/TiO2-Schottky-diode based plasmonic hot-electron photodetector. This detector shows a high detectivity of 9.8 × 1010 cmHz1/2/W and a fast response speed, with a rise and fall time of 112 μs and 24 μs, respectively, under 450 nm light illumination at zero bias voltage. In addition, the height of the Ag/TiO2 Schottky barrier can be decreased by removing the chemisorbed oxygen from the surface of TiO2 with ultraviolet light illumination, and as a result, the responsivity of the Ag/TiO2 plasmonic hot-electron photodetector at 450 nm can increase from 3.4 mA/W to 7.4 mA/W.

This paper presents a systematic study of Raman spectra of nanocomposite photonic crystals produced using opal matrices or anodic aluminum oxide and filled with various inorganic compounds. We compare Raman spectra of the starting inorganic compounds (K2Cr2O7, CrO3, and KIO3) and nanocomposite photonic crystals whose pores are filled with the inorganic substances. Our results open up the possibility of producing high-performance sensors of inorganic substances introduced into the pores of photonic crystals, based on analysis of enhanced Raman scattering in a nanocomposite photonic crystal.

In this article, pure and tungsten-doped (W-doped) highly ordered two-dimensional (2D) vanadium dioxide (VO2) nanowire arrays were successfully prepared by a hydrothermal treatment, followed by a self-assembly progress and the in-situ high temperature treatment. The infrared photodetector devices based on monoclinic VO2 (VO2(M)) and W-doped VO2(M) nanowires were comparatively studied . It was found that the device based on W-doped VO2(M) nanowires exhibits a rapid infrared response and an enhanced photoelectric responsivity of 21.4 mA/W under the incident infrared light intensity of 280 mW/cm2, which is nearly two orders of magnitude superior to pure VO2(M) nanowire array. Our experimental results provided a direct and convenient path for design of future high-performance photodetector devices.

The angular dependences of the transmission of a one-dimensional photonic crystal based on porous anodic aluminum oxide are studied in the wavelength range of 320–1200 nm. The possibility of using porous one-dimensional photonic crystals based on aluminum oxide as selective narrowband optical filters and mirrors is studied.

Tb3+-doped TiO2 (TiO2:Tb3+) films are synthesized by a facile sol-gel method. The hot-electron current of Au/TiO2:Tb3+ Schottky diodes was enhanced by UV light decreasing the height of Schottky barrier. Compared with pure TiO2, doping Tb3+ can reduce the background current originating from the internal photoelectric effect in TiO2, and improve the on/off ratio. This is due to the energy and charge transfer mechanism from TiO2 to Tb3+. Photogenerated electrons in TiO2:Tb3+ films excited by UV light can be consumed by radiative electron transitions from the level 5D4 to the 7Fj (j=6, 5, 4, 3) for Tb3+. This is beneficial and effective to regulate the electronic state of optoelectronic materials.

Herein, we report an enhanced tunable broadband wavelength-selective lead sulfide (PbS) film detector integrated with Au-nanorod arrays that were obtained by using an ultrathin open-ended porous titanium dioxide membrane (UOP-TM) as a mask. The responsivity of the PbS films with periodic Au-nanorods exhibits a drastic enhancement by up to 125%–175% due to the enhancement of the localized electromagnetic fields around the gold nanorods. Notably, the location of the strongest enhancement peak of photocurrent shifted from 450 to 980 nm as the height of the Au-nanorods increased from 30 to 120 nm. In addition, the responsivity and detectivity of the hybrid PbS film modified with 90 nm Au-nanorod arrays under laser illumination of 980 nm are as high as 944 mA W−1 and 1.72 × 1010 cm Hz1/2 W−1, respectively. These excellent figures-of-merit of the tunable broadband plasma-enhanced PbS films could be a promising candidate in future wavelength-selective photodetector applications.

Designing and fabrication of the infrared antireflection coatings are quite important for the application of infrared optical elements. Herein, double-layer two wavelength infrared antireflective (AR) coating was prepared on CdSe substrate by sol-gel method, in which the bottom layer is porous TiO2 film and the top layer is SiO2 nanoparticle film containing a small amount of TiO2 (molar ratio of Si/Ti is 7.7). The reflectivity of the coated sample is about 2.1% at 2000 nm and 2.8% at 2500 nm, respectively, and the average reflectivity of the whole wide band from 1800 nm to 2600 nm is about 2.6%, which is about 27% lower than that of uncoated CdSe substrate. By adding reasonable additives and designing the film structure, the problem that thick infrared film is not resistant to high temperature annealing was solved. Moreover, the AR coating shows a super hydrophilicity, which can avoid the influence of water mist condensation on the transmittance. Importantly, this AR coating exhibits a good thermal shock resistance, and the reflection spectrum of the film did not change after ten thermal shock cycles at 400 °C, which meaning this film can be expected to meet the requirements of high temperature irradiation environment. This work provides important guidance for the preparation of infrared AR film with high thermal stability.

High-quality Sn2+-sensitized PbS films were deposited via a cost‐effective chemical route. The results demonstrate that the Sn2+-sensitized PbS thin films have better crystallinity and larger grain size. Photoelectric performance of Sn2+-sensitized PbS films has been improved greatly in the visible and near-infrared range. With Sn2+ sensibilization, photoresponsivity is more than 9 times higher, and detectivity is as high as ~1010 cm2 Hz1/2 W−1. Notably, the response speed of the Sn2+-sensitized PbS films reaches a magnitude of microseconds, which is over 105 times improvements compared with the pure PbS film devices. Additionally, high-frequency switching behavior at 4 kHz shows excellent stability. Based on the feasible method and excellent photoelectric performance of the devices, it has been demonstrated that Sn2+ sensibilization is of viability to improve the detection performance of commercial photodetectors.

A type of metal-semiconductor-metal (MSM) photodetector based on PbTe single-crystalline nanowires was prepared. I–V characteristics of the photodetector in the temperature range of 77–300 K were studied. Little dark current was achieved in MSM PbTe nanowire photodetector at low bias voltages due to the formation of back to back Schottky junctions between the PbTe nanowires and Au electrodes. The influences of light intensity, bias voltage, and temperature on the performance of PbTe nanowire photodetector were investigated. It was found that the photocurrent is linear to light intensity. The photosensitivity of the typical photodetector was about 50% and varied only slightly as a function of bias voltage. Moreover, this photodetector displayed a fast respond compared with nanoparticle photodetector due to the one dimensional structure and the high crystallinity of nanowires.

In this paper, we fabricate ordered pore array (OPA) Ag film coated glass with the aid of polystyrene sphere (PS) array templates. This kind of OPA Ag coated glass has optical advantages of visible transparency, blue and near-infrared resistance. The average visible transmittance is 68%, including a transmission peak of 78% located at 570 nm, and low average transmittance of 48% in the blue light region that is not damaging to the eyes. The near-infrared light blocking rate is 67%, among which 40% light is reflected directly, indicating the reflection domination.