Failure causes and mechanisms of retrofit LED lamps

Santi, Carlo De; Lago, Matteo Dal; Buffolo, Matteo; Monti, Desiree; Meneghini, Matteo; Meneghesso, Gaudenzio; Zanoni, Enrico

doi:10.1016/j.microrel.2015.06.080

Cited by 19 publications

(9 citation statements)

References 14 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The PL stability within the RT phase limit is further supported by the determined CIE chromaticity coordinates of (0.53, 0.45) at 415 K and the colorrendering index (CRI) value of 73, which are very close to the RT recorded values of (0.55, 0.42) and 75, respectively, verifying the excellent high-temperature emission performance of the material. This finding is important because an LED operating temperature can be as high as 425 K. 81,82 Film Deposition. A highly attractive feature of (DAO)Sn 2 I 6 is its ability to deposit uniform high-quality thin films.…”

Section: ■ Results and Discussionmentioning

confidence: 99%

Water-Stable 1D Hybrid Tin(II) Iodide Emits Broad Light with 36% Photoluminescence Quantum Efficiency

Spanopoulos

Hadar

et al. 2020

J. Am. Chem. Soc.

View full text Add to dashboard Cite

The optical and light emission properties of tin and lead halide perovskites are remarkable because of the robust room temperature performance, broad wavelength tunability, high efficiency and good quenching-resistance to defects. These highly desirable attributes promise to transform current light emitting devices, phosphors and lasers. One disadvantage in most of these materials is the sensitivity to moisture. Here we report a new air-stable one-dimensional (1D) hybrid lead-free halide material (DAO)Sn 2 I 6 (DAO: 1,8-octyldiammonium) that is resistant to water for more than 15h.The material exhibits a sharp optical absorption edge at 2.70 eV and a strong broad orange light emission centered at 634 nm, with a full width at half maximum (FWHM) of 142 nm (0.44 eV). The emission has a long photoluminescence (PL) lifetime of 582 ns, while the intensity is constant over a very broad temperature range (145-415 K) with a photoluminescence quantum yield (PLQY) of at least 20.3% at RT. Above 415 K the material undergoes a structural phase transition from monoclinic (C2/c) to orthorhombic (Ibam) accompanied by a red shift in the bandgap and a quench in the photoluminescence emission. Density functional theory calculations support the trend in the optical properties and the 1D electronic nature of the structure, where the calculated carrier effective masses along the inorganic chain are significantly lower than those perpendicular to the chain. Thin films of the compound readily fabricated from solutions exhibit the same optical properties, but with improved PLQY of 36%,

show abstract

Section: ■ Results and Discussionmentioning

confidence: 99%

Water-Stable 1D Hybrid Tin(II) Iodide Emits Broad Light with 36% Photoluminescence Quantum Efficiency

Spanopoulos

Hadar

et al. 2020

J. Am. Chem. Soc.

View full text Add to dashboard Cite

show abstract

“…While limited stability of the electric drive circuitry rather than the degradation of the LEDs themselves has already been identified as a potential problem several years ago [27] and efforts to improve these by avoiding semiconductor switches and electrolytic capacitors all together have been reported [28], we are not aware of experimental studies as detailed as this in investigating LED light failures of individual complete commercial devices.…”

Section: Discussionmentioning

confidence: 99%

Failure Analysis of Some Commercial Spotlights Based on Light Emitting Diodes

Zhong

Walther

2021

Electronics

View full text Add to dashboard Cite

The failure mechanism of two commercial light-emitting diode (LED)-based spotlights with GU10 form factor is analyzed. Through component testing and comparison to nominal values as well as to simulations, it is found that the cause of both device failures is related to damaged components within the drive circuits rather than the LEDs themselves. Both LED heads work as normal when connected to an external direct current (DC) source. The results show that the lack of light output of one spotlight is related to the open circuit caused by damaged resistors and inductors in its drive circuit, while the flickering of the other is related to the malfunction of the integrated circuit providing constant current output. Therefore, improving the quality of the LED drive circuits is considered the most effective way for manufacturers to reduce catastrophic failures of LED spotlights.

show abstract

“…Just as it is important to ensure that the temperature of the devices is kept within limits, it is also of importance to ensure the heat generation in the device doesn't significantly increase the ambient temperature. This is due to the fact that the LED optical output is significantly affected by the temperature as presented in [4,5]. In [5] the optical output was while altering the ambient temperature.…”

Section: Package Thermal Designmentioning

confidence: 99%

Chip-on-board assembly of 800V Si L-IGBTs for high performance ultra-compact LED drivers

Aliyu

Mouawad

Castellazzi

et al. 2017

2017 29th International Symposium on Power Semiconductor Devices and IC's (ISPSD)

View full text Add to dashboard Cite

Abstract-This paper presents a novel chip on board assembly design for an integrated power switch, based on high power density 800V silicon lateral insulated-gate bipolar transistor (Si LIGBT) technology. LIGBTs offer much higher current densities (5-10X), significantly lower leakage currents, and lower parasitic device capacitances and, gate charge compared to conventional vertical MOSFETs commonly used in LED drivers. The higher voltage ratings offered (up to 1kV), the development of high voltage interconnection between parallel IGBTs, self-isolated nature and absence of termination region unlike in a vertical MOSFET makes these devices ideal for ultracompact, low bill of materials (BOM) count LED drives. Chip onboard LIGBTs also offer significant advantages over MOSFETs due to high ambient temperatures seen on most of the LED lamps as the LIGBTs on-state losses increase only marginally with temperature. The design is based on a built-in reliability approach which focuses on a compact LED driver as a case-study of a cost-sensitive large volume production item.

show abstract

Failure causes and mechanisms of retrofit LED lamps

Cited by 19 publications

References 14 publications

Water-Stable 1D Hybrid Tin(II) Iodide Emits Broad Light with 36% Photoluminescence Quantum Efficiency

Water-Stable 1D Hybrid Tin(II) Iodide Emits Broad Light with 36% Photoluminescence Quantum Efficiency

Failure Analysis of Some Commercial Spotlights Based on Light Emitting Diodes

Chip-on-board assembly of 800V Si L-IGBTs for high performance ultra-compact LED drivers

Contact Info

Product

Resources

About