Light source at liquid nitrogen temps

Click For Summary
SUMMARY

The discussion centers on finding a suitable white light source for use in a cryostat at temperatures down to 77 K for temperature-dependent studies of photovoltaic (PV) devices. The current incandescent bulb has degraded in performance, shifting its spectrum towards red, prompting the search for a solid-state alternative. Participants suggest considering Luxeon 5W white LEDs, although concerns about their performance at low temperatures and potential red shifting are noted. The operating temperature range for Luxeon LEDs is -40°C to +135°C, which may not meet the experimental requirements.

PREREQUISITES
  • Understanding of cryogenic environments and their effects on materials
  • Familiarity with photovoltaic device testing methodologies
  • Knowledge of solid-state lighting technologies, specifically LED characteristics
  • Basic principles of light spectrum and color temperature
NEXT STEPS
  • Research solid-state lighting options specifically designed for cryogenic applications
  • Investigate the performance of LEDs at cryogenic temperatures, focusing on red shifting
  • Explore alternative light sources suitable for low-temperature environments
  • Learn about solar simulators and their integration with fiber optics for cryostat use
USEFUL FOR

Researchers and engineers involved in cryogenic experiments, particularly those studying photovoltaic devices and seeking effective lighting solutions at low temperatures.

232Thorium
Messages
4
Reaction score
0
Can anyone recommend a white light source to be used in a cryostat down to 77 K? We are using it in temperature-dependent studies of PV devices. Currently we have an incandescent bulb which has shifted its spectrum towards red over time and we're looking for a replacement. It would be nice to have a solid-state source since the incandescent bulb obviously heats up quite a bit, but I don't know of any that work at such low temps.

It should be a small bulb, about the size of the middle segment of a finger. (Weird comparison, I know, but I was looking around my desk for something that people on the forum could relate to for size and this does the trick :smile:.)

We'd eventually like to run a solar simulator hooked up to fiber optics to get the light down the cryostat, but for now we're looking for a new bulb as a temporary fix. Thanks!
 
Physics news on Phys.org
Can you use an LED? Luxeon makes 5W white ones that are incredibly bright.
 
I would love to, but as I understand it, LEDs either suffer significant red shifting upon cooling or else stop working completely. A Youtube search gave some interesting demos of this. I will check it out and report back.

Also, I looked up Luxeon LEDs and they are all rated with an operating temperature of -40°C to +135°C, which isn't good enough for our experiments. I may buy one and see what happens outside of their listed range. Thanks for the tip.
 
Last edited:

Similar threads

Undergrad Tips on generating entangled photon pair with SPDC entanglement source
  • · Replies 1 ·
Replies
1
Views
2K
Undergrad How to measure the wavelength of a light source
  • · Replies 7 ·
Replies
7
Views
21K
High School Infrared Detectors & The 2nd Law of Thermodynamics
  • · Replies 152 ·
6
Replies
152
Views
11K
Graduate Cherenkov Radiation for lighting
  • · Replies 1 ·
Replies
1
Views
6K
Kerbal Space Program - Rocket Design Basics
  • · Replies 2 ·
Replies
2
Views
10K
Mathematica This Week's Finds in Mathematical Physics (Week 264)
  • · Replies 6 ·
Replies
6
Views
5K