Jovial Monk wrote on Mar 22
nd, 2017 at 7:04am:
My greenhouse warmed because light entering, being converted to IR and the IR trapped by the walls of the greenhouse.
Wow. Can you describe the mechanism? The only thing I can find about converting visible light to IR is a suggestion to paint something black.

Not optimal for a greenhouse.
But what you seem to be saying is more IR causes more heat.
Although there seems to be this -
"We show that Ce3+ can be an efficient sensitizer for Yb3+ in the host lattice of yttrium aluminum garnet (YAG). With blue-light excitation to induce the 4𝑓→5𝑑 transition of Ce3+, characteristic near-IR emission of Yb3+ due to transition of 𝐹5⁄22→𝐹7⁄22 peaking at 1030 nm is generated as a result of energy transfer from Ce3+ to Yb3+. The result of spectral evolution with temperature indicates that the efficiency of energy transfer is enhanced owing to thermal effect. This evidence implies that the phonon-assisted process participates in the downconversion of YAG: Ce3+, Yb3+."
https://www.osapublishing.org/ol/abstract.cfm?uri=ol-34-22-3565Conversion to NEAR infrared.
Very hightech. Also plenty of papers converting IR to visible light - also hightech.
You didn't say you had a hightech greenhouse.