Osram achieves a new efficiency record with its 660 nm "Hyper Red" diodes. Beyond 4.5 µmol/J, the third generation Oslon Square - the GH CSSRM4.24 (Data sheet) above the competition from Cree and Samsung.
The most recent APEXengine 660 Mk II now relies on these highly efficient LED chips.
The deep red light colour at 660 nm has a physical advantage in terms of efficiency. The Unit of measurement PAR is in fact based on the counting of Photons in the 400 - 700 nm range.
Longer-wave red light is not as energetic as blue or even UV radiation. This means that less energy is needed to emit a red photon.
For this reason in particular - and because light in the red spectrum plays an important role in the flowering phase and photomorphogetic effects - red light is the preferred light for plant lighting.
Many LED semiconductor manufacturers provide data on the efficiency of red LEDs. The photosynthetic photon efficiency (PPE) is given in µmol/J and describes how many photons are emitted in the range of 400 - 700 nm per applied energy.
In the current comparison, Osram is at the top with the GH CSSRM4.24 (as of October 2020).
In the Oslon Square series, Osram is using larger LED chips than usual to achieve the impressive performance figures. The Oslon Square Hyper Red LED has been available with a 2 mm² chip ("Die") since the end of 2017. The third generation since the GH CSSRM4.24 now has a power output of over 75 %.
Thanks to this development, system efficiencies above 3.0 µmol/J are no longer a pipe dream. The system efficiency also takes into account driver and optical losses. Commercial LED grow lamps of well-known manufacturers are recently offered with very high efficiencies of about 2.7-2.8 µmol/J.
Crescience offers with the APEXengine 660 Mk II an easy to handle LED module with Osram GH CSSRM4.24. In combination with FLUXengine and modern Mean Well drivers plant lamps with system efficiencies above 3.0 µmol/J can be constructed.

There is already the Oslon Square 6.24 with PPF/W 4.48 @700mA in the low VA bin and even 4.71 in the A3 bin... There is only one bingroup left.
Radiant Efficiency: typ. 81% @ 700mA; typ. 86% @ 350mA
Photon Flux Efficacy: typ 4.42 μmol/J @ 700mA; typ 4.74 μmol/J @ 350mA
The A3-bin @350mA should be approx. 5.1umols/W.
It's time for an APEX 660 MK4
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