SwePub
Sök i LIBRIS databas

  Utökad sökning

onr:"swepub:oai:research.chalmers.se:2ffc19e7-3ba8-4490-ba53-e5e80da8381c"
 

Sökning: onr:"swepub:oai:research.chalmers.se:2ffc19e7-3ba8-4490-ba53-e5e80da8381c" > Towards ultraviolet...

LIBRIS Formathandbok  (Information om MARC21)
FältnamnIndikatorerMetadata
00005708naa a2200469 4500
001oai:research.chalmers.se:2ffc19e7-3ba8-4490-ba53-e5e80da8381c
003SwePub
008221029s2018 | |||||||||||000 ||eng|
0247 a https://research.chalmers.se/publication/5328242 URI
040 a (SwePub)cth
041 a engb eng
042 9 SwePub
072 7a kon2 swepub-publicationtype
072 7a ref2 swepub-contenttype
1001 a Bergmann, Michael Alexander,d 1989u Chalmers tekniska högskola,Chalmers University of Technology4 aut0 (Swepub:cth)micale
2451 0a Towards ultraviolet and blue microcavity lasers
264 1c 2018
520 a The development of III-nitride-based (Al,Ga,In(N)) microcavity lasers is a challenging task. Significant progress in recent years has resulted in realizations of electrically pumped devices with optical output power in the mW-range and with threshold current densities below 20 kA/cm2. However, to become practical, the lifetime and power conversion efficiency of these devices must be improved. Among the challenges are achieving transverse optical mode confinement, highreflectivity mirrors and control over the resonator length. We will highlight our theoretical work on transverse optical mode confinement, emphasising the overwhelming risk of ending up with an optically anti-guided cavity, and its consequences such as very high optical losses that easily could double the threshold gain for lasing. We will show some anti-guided cavities with reasonable threshold gain and built-in modal discrimination. However, all anti-guided cavities are very sensitive to temperature effects and small structural changes in the cavity caused by fabrication imperfections. We have explored electrically conductive distributed Bragg reflectors (DBRs) in both AlN/GaN and ZnO/GaN. The AlN/GaN DBRs were grown with different strain-compensating interlayers, and the DBR without interlayers had the lowest vertical resistivity with a specific series resistance of 0.044 cmfor eight DBRpairs. In the ZnO/GaN DBR, the measured resistance was dominated by lateral and contact contributions, setting a lower measurable limit of ~10 for three DBR-pairs. Numerical simulations show the importance of having in-plane strained layers in the ZnO/GaN DBR, since that leads to cancellation of the spontaneous and piezoelectric polarization. This results in a dramatically reduced vertical resistance, potentially three orders of magnitude lower than what could be measured. cm An alternative to an epitaxially grown DBR is a dielectric DBR, which offers high reflectivity over a broader wavelength range, relaxing the requirements on resonator length control. To deposit a dielectric DBR on the bottom side of the cavity, the sample must first be bonded to a carrier wafer before the substrate can be removed. We used thermocompression gold-gold bonding to successfully bond the laser structure to a Si carrier wafer. The subsequent substrate removal is a challenging process due to the chemical inertness of the III-nitride-based materials. A doping-dependent electrochemical etch technique was used, which allows for the selective removal of a sacrificial (n-doped) layer between the cavity and the substrate. This resulted in nm-precise cavity lift-off with a low root-mean-square surface roughness down to 0.3 nm. Thus, the process is suitable for the fabrication of high-quality optical devices such as microcavity lasers. In addition, the technique offers a new alternative to create III-nitridebased optical resonators, mechanical resonators, thin film LEDs and transistors.
650 7a NATURVETENSKAPx Fysik0 (SwePub)1032 hsv//swe
650 7a NATURAL SCIENCESx Physical Sciences0 (SwePub)1032 hsv//eng
650 7a TEKNIK OCH TEKNOLOGIERx Materialteknikx Annan materialteknik0 (SwePub)205992 hsv//swe
650 7a ENGINEERING AND TECHNOLOGYx Materials Engineeringx Other Materials Engineering0 (SwePub)205992 hsv//eng
650 7a TEKNIK OCH TEKNOLOGIERx Elektroteknik och elektronik0 (SwePub)2022 hsv//swe
650 7a ENGINEERING AND TECHNOLOGYx Electrical Engineering, Electronic Engineering, Information Engineering0 (SwePub)2022 hsv//eng
650 7a TEKNIK OCH TEKNOLOGIERx Nanoteknik0 (SwePub)2102 hsv//swe
650 7a ENGINEERING AND TECHNOLOGYx Nano-technology0 (SwePub)2102 hsv//eng
653 a ultraviolet
653 a electrochemical etching
653 a microcavity laser
653 a DBR
653 a blue
7001 a Hjort, Filip,d 1991u Chalmers tekniska högskola,Chalmers University of Technology4 aut0 (Swepub:cth)filiphj
7001 a Hashemi, Seyed Ehsan,d 1986u Chalmers tekniska högskola,Chalmers University of Technology4 aut0 (Swepub:cth)eseyed
7001 a Adolph, David,d 1971u Chalmers tekniska högskola,Chalmers University of Technology4 aut0 (Swepub:cth)adolph
7001 a Stattin, Martin,d 1983u Chalmers tekniska högskola,Chalmers University of Technology4 aut0 (Swepub:cth)stattin
7001 a Ive, Tommy,d 1968u Chalmers tekniska högskola,Chalmers University of Technology4 aut0 (Swepub:cth)itommy
7001 a Bengtsson, Jörgen,d 1968u Chalmers tekniska högskola,Chalmers University of Technology4 aut0 (Swepub:cth)jorgenb
7001 a Gustavsson, Johan,d 1974u Chalmers tekniska högskola,Chalmers University of Technology4 aut0 (Swepub:cth)johangus
7001 a Haglund, Åsa,d 1976u Chalmers tekniska högskola,Chalmers University of Technology4 aut0 (Swepub:cth)gu95asha
7102 a Chalmers tekniska högskola4 org
7730 t Northen Optics and Photonics conferenceg 2018q 2018z 9789163964886
8564 8u https://research.chalmers.se/publication/532824

Hitta via bibliotek

Till lärosätets databas

Kungliga biblioteket hanterar dina personuppgifter i enlighet med EU:s dataskyddsförordning (2018), GDPR. Läs mer om hur det funkar här.
Så här hanterar KB dina uppgifter vid användning av denna tjänst.

 
pil uppåt Stäng

Kopiera och spara länken för att återkomma till aktuell vy