LEDs ♦ news digest
QDEF solution specifically to deliver more colour, and to make devices such as smart phones, tablets and televisions, lighter, brighter and more energy efficient.
Current LCDs typically are limited to displaying 35 percent or less of the visible color spectrum. This means the viewing experience on an LCD can be vastly different than what a person sees in the real world. Wide colour gamut displays will allow consumers to enjoy more visceral, more immersive and truer-to-life colour.
CFN’s Kim Kisslinger, seen here with a focused-ion beam instrument, reduced the InGaN samples to a thickness of just 20 nm to prepare them for electron microscopy
The research was supported by the Centre for Excitonics, an Energy Frontier Research Centre funded by the U.S. Department of Energy’s Office of Science. The work at Brookhaven Lab’s Centre for Functional Nanomaterials was also supported by DOE’s Office of Science, with additional work carried out at the MIT Centre for Materials Science Engineering.
“The Centre for Excitonics gave us the freedom and funding to look at this fundamental question, knowing that these explorations will ultimately push the limits of LED technology,” Gradečak says. “This was a strong collaboration between MIT and Brookhaven’s CFN, demonstrating the concentration of expertise and instrumentation that really pushes science and technology forward.”
Further details of this work has been published in the paper, “Revisiting the “In-clustering” question in InGaN through the use of aberration-corrected electron microscopy below the knock-on threshold,” by Kamal H. Baloch et al in Applied Physics Letters, 102, 191910 (2013).
http://dx.doi.org/10.1063/1.4807122
3M and Nanosys stunningly enhance LCDs with quantum dots
Pumped with a blue source, such as the gallium nitride (GaN) LED, quantum dots can be made to emit at any wavelength beyond the pump source wavelength with over 90 percent quantum yield
3M has announced it is in the final stages of scale-up for its new 3M Quantum Dot Enhancement Film (QDEF).
The new film allows up to 50 percent more color than current levels in liquid crystal display (LCD) devices.
3M has teamed up with Nanosys, to produce the 3M
Comparison of LCDs without (left) and with (right) 3M’s QDEF solution. (Photo: 3M)
“One of the many advantages of the new 3M QDEF solution is the film’s ability to deliver richly-saturated colours, while minimising power consumption - a difference you can clearly see,” says Ty Silberhorn, vice president and general manager, 3M Optical Systems Division. “We will have qualification material available to customers for design cycles starting late second quarter this year.”
Over the years, 3M light management technologies have made LCDs thinner, lighter and more energy efficient. Colour performance of LCDs industry-wide has gone largely unchanged until now. 3M research data shows that devices with 3M QDEF-enabled wide colour gamut will be noticeably different from other standard LCD devices, prompting the human eye to dwell on the display longer than less-saturated displays.
QDEF utilises the light emitting properties of quantum dots to create an ideal backlight for LCDs, which is one of the most critical factors in the coluor and efficiency performance of LCDs.
Unlike conventional phosphor technologies such as YAG that emit with a fixed spectrum, quantum dots can actually convert light to nearly any color in the visible spectrum.
Pumped with a blue source, such as a GaN LED, they can be made to emit at any wavelength beyond the pump source wavelength with very high efficiency (over 90 percent quantum yield) and with very narrow spectral distribution (only 30 - 40nm FWHM.)
June 2013
ww.compoundsemiconductor.net 75
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60 |
Page 61 |
Page 62 |
Page 63 |
Page 64 |
Page 65 |
Page 66 |
Page 67 |
Page 68 |
Page 69 |
Page 70 |
Page 71 |
Page 72 |
Page 73 |
Page 74 |
Page 75 |
Page 76 |
Page 77 |
Page 78 |
Page 79 |
Page 80 |
Page 81 |
Page 82 |
Page 83 |
Page 84 |
Page 85 |
Page 86 |
Page 87 |
Page 88 |
Page 89 |
Page 90 |
Page 91 |
Page 92 |
Page 93 |
Page 94 |
Page 95 |
Page 96 |
Page 97 |
Page 98 |
Page 99 |
Page 100 |
Page 101 |
Page 102 |
Page 103 |
Page 104 |
Page 105 |
Page 106 |
Page 107 |
Page 108 |
Page 109 |
Page 110 |
Page 111 |
Page 112 |
Page 113 |
Page 114 |
Page 115 |
Page 116 |
Page 117 |
Page 118 |
Page 119 |
Page 120 |
Page 121 |
Page 122 |
Page 123 |
Page 124 |
Page 125 |
Page 126 |
Page 127 |
Page 128 |
Page 129 |
Page 130 |
Page 131 |
Page 132 |
Page 133 |
Page 134 |
Page 135 |
Page 136 |
Page 137 |
Page 138 |
Page 139 |
Page 140 |
Page 141 |
Page 142 |
Page 143 |
Page 144 |
Page 145 |
Page 146 |
Page 147 |
Page 148 |
Page 149 |
Page 150 |
Page 151 |
Page 152 |
Page 153 |
Page 154 |
Page 155 |
Page 156 |
Page 157 |
Page 158 |
Page 159 |
Page 160 |
Page 161 |
Page 162 |
Page 163 |
Page 164 |
Page 165 |
Page 166 |
Page 167 |
Page 168 |
Page 169 |
Page 170 |
Page 171 |
Page 172 |
Page 173 |
Page 174 |
Page 175 |
Page 176 |
Page 177 |
Page 178 |
Page 179 |
Page 180 |
Page 181 |
Page 182 |
Page 183 |
Page 184 |
Page 185 |
Page 186 |
Page 187 |
Page 188 |
Page 189 |
Page 190 |
Page 191