Editing Fluorescent lamp (section)

===Phosphor composition===
{{Unreferenced section|date=May 2024}}
Some of the least pleasant light comes from tubes containing the older, [[calcium halophosphate]] [[phosphor]]s (chemical formula [[calcium|Ca]]<sub>5</sub>([[phosphorus|P]][[oxygen|O]]<sub>4</sub>)<sub>3</sub>([[fluorine|F]], [[chlorine|Cl]]):[[antimony|Sb]]<sup>3+</sup>, [[manganese|Mn]]<sup>2+</sup>). This phosphor mainly emits yellow and blue light, and relatively little green and red. In the absence of a reference, this mixture appears white to the eye, but the light has an incomplete [[spectrum]]. The [[color rendering index]] (CRI) of such lamps is around 60.

Since the 1990s, higher-quality fluorescent lamps use a [[Rare-earth element|rare-earth]] tri-phosphors mixture, based on [[europium]] and [[terbium]] ions, which have emission bands more evenly distributed over the spectrum of visible light, but with peaks in the red, green and blue. Triphosphor tubes give a more natural color reproduction to the human eye. The CRI of such lamps is typically 85.

{| class="wikitable"
|+ Fluorescent-lamp spectra
|-
| Typical fluorescent lamp with [[rare-earth]] phosphor || [[File:Fluorescent lighting spectrum peaks labeled with colored peaks added.png|frameless]] || A typical "cool white" fluorescent lamp utilizing two rare-earth-doped phosphors, [[terbium|Tb]]<sup>3+</sup>, [[cerium|Ce]]<sup>3+</sup>:[[lanthanum|La]]PO<sub>4</sub> for green and blue emission and [[europium|Eu]]:[[yttrium|Y]]<sub>2</sub>O<sub>3</sub> for red. For an explanation of the origin of the individual peaks click on the image. Several of the spectral peaks are directly generated from the mercury arc. This is likely the most common type of fluorescent lamp in use today.
|-
| An older-style halophosphate-phosphor fluorescent lamp || [[File:Spectrum of halophosphate type fluorescent bulb (f30t12 ww rs).png|frameless]] || Halophosphate phosphors in these lamps usually consist of trivalent [[antimony]]- and divalent [[manganese]]-doped [[calcium]] halophosphate (Ca<sub>5</sub>(PO<sub>4</sub>)<sub>3</sub>([[chlorine|Cl]], [[fluorine|F]]):Sb<sup>3+</sup>, Mn<sup>2+</sup>). The color of the light output can be adjusted by altering the ratio of the blue-emitting antimony dopant and orange-emitting manganese dopant. The color rendering ability of these older-style lamps is quite poor. Halophosphate phosphors were invented by A. H. McKeag ''et al.'' in 1942.
|-
| "Natural sunshine" fluorescent light || [[File:Spectra-Philips 32T8 natural sunshine fluorescent light.svg|frameless]] || Peaks with stars are [[mercury (element)|mercury]] lines.
|-
| Yellow fluorescent lights || [[File:Yellow fluorescent light spectrum.png|frameless]] || The spectrum is nearly identical to a normal fluorescent lamp except for a near total lack of light shorter than 500 nanometers. This effect can be achieved through either specialized phosphor use or more commonly by the use of a simple yellow light filter. These lamps are commonly used as lighting for [[photolithography]] work in [[cleanrooms]] and as "bug repellent" outdoor lighting (the efficacy of which is questionable).
|-
| Spectrum of a "[[blacklight]]" lamp || [[Image:Fluorescent Black-Light spectrum with peaks labelled.gif|frameless]] || There is typically only one phosphor present in a blacklight lamp, usually consisting of [[europium]]-doped [[strontium]] [[borate|fluoroborate]], which is contained in an envelope of [[Wood's glass]].
|}