Air-processed stable near-infrared Si-based perovskite light-emitting devices with efficiency exceeding 7.5%

Two composite layers are used to enhance the efficiency of Si-based near-infrared perovskite light-emitting devices, which are produced in ambient air, and the external quantum efficiency increased to 7.5%.

Памяти Е.М. Круглова и Филимонова В.В. Квантовый выход кремниевого лавинного фотодиода в диапазонах длин волн 114-170 и 210-1100 nm

Avalanche silicon photodiode have been developted for near ir, visible, UV and VUV light range. External quantum efficiency have been studied in 114 - 170 abd 210 - 1100nm range. It is demonstrated that photodiode reach from 29 to 9300 electrons/photon on 160 nm with bias voltage of 190 and 303 v respectively.

New facility for primary calibration of differential spectral responsivity of solar cells using LDLS-based monochromatic source

A newly established setup for primary calibration and characterization of solar cells at NMCC/SASO is presented. This differential spectral responsivity (DSR) measurement instrument uses laser-driven light source (LDLS)-based modulated (AC) source to measure the spectral responsivity of photovoltaic (PV) detectors and solar cells. The setup is intended for measuring the spectral responsivity in the wavelength range from 250 nm to 2000 nm, bias level up to 1.5 kW/m2, with which a measurement uncertainty of 1.06 % (k = 2, in the range of 300 nm to 900 nm) could be achieved. We present validation measurements as well as spectral responsivity and external quantum efficiency (EQE) measurements of reference solar cells to demonstrate the objective of the setup. We present a preliminary evaluation of the associated uncertainty components as well as an uncertainty budget for validation, optimization and standardization of our setup.

Correction: Luminescent columnar discotics as highly efficient emitters in pure deep-blue OLEDs with an external quantum efficiency of 4.7%

Correction for ‘Luminescent columnar discotics as highly efficient emitters in pure deep-blue OLEDs with an external quantum efficiency of 4.7%’ by Joydip De et al., Soft Matter, 2022, DOI: 10.1039/d1sm01558c.

Деградация ультрафиолетовых светодиодов с квантовыми ямами InGaN/GaN, вызванная кратковременными воздействиями током

A comparative analysis of the initial stages of degradation of ultraviolet and blue LED structures with InGaN / GaN quantum wells is carried out. In the mode of accelerated aging, the structures were subjected to short-term, sequential exposure to currents of 80–190 mA at forward bias. The exposure time did not exceed three hours. There was an increase (up to 20%) in the external quantum efficiency. The most probable physical mechanisms explaining the changes in InGaN / GaN LEDs are presented and possible ways to slow down the aging of UV LEDs are outlined.

High-performance narrow spectrum green phosphorescent top-emitting organic light-emitting devices with external quantum efficiency up to 38%

In this work, we have experimentally demonstrated the efficacy of micro-cavity effect in realizing high-performance top-emitting organic light-emitting diodes (TEOLEDs). By optimizing the thickness of top Yb/Ag electrode and cavity length, highly efficient green TEOLED with external quantum efficiency as high as 38% was achieved. A strong dependence of electroluminescent (EL) performances and spectrum on cavity length was observed, and there was also a significant angle dependence of EL spectrum. Ultimately, ultra-high current efficiency up to 161.17 cd/A (3.2 V) was obtained by the device with emission peak at 552 nm, which is 35 nm longer than the intrinsic emission peak (517 nm) of utilized green emitter. Interestingly, this device displayed narrow emission with full-width at half-maximum (FWHM) of less than 20 nm, which was obtained by increasing the Ag layer thickness.

Several processes participating in a decrease and the droop of external quantum efficiency in green InGaN/GaN MQW structures

The obtained experimental results allow us to clarify the nature of mechanisms related to the presence of cations in disordered InGaN alloy and hetero-interfaces. The capture of charge carriers by cations reduces the external quantum efficiency (EQE) in green MQWs at j < 10 A/cm2. The EQE droop phenomenon caused by smoothed out lateral potential fluctuations occurs at j > 10 A/cm2. At j > 40 A/cm2 the droop associated with interactions between charge carriers and dislocations and grain boundaries takes place.