Organic light-emitting diodes (OLEDs) are optoelectronic devices that convert electricity into light. Since their development in the late 80's, 1 they represent a sustainable lightning technology and have been applied to various displays (screens, phones) or lightning panels. The first generation of OLEDs was based on fluorescent emitters. This technology allowed the field to rapidly expand but suffered from its intrinsic efficiency limit to an internal quantum efficiency (IQE) of 25%. This limit was then overcome with the use of phosphorescent emitters or Thermally Activated Delayed Fluorescent emitters (IQE = 100%). These two technologies now represent the benchmark OLED devices. However, the combination of fluorescent emitters with a TADF assistant dopant (the so called TADF Sensitized Fluorescence TSF) appears as an elegant alternative to produce efficient OLEDs with high color purity. In addition, purely fluorescent electroluminescent materials are also expected to have a great potential in the field of electrically pumped organic lasers, where triplet states are highly detrimental, or in Visible Light Communications (VLC) that need ultrafast response excluding the use of triplet emitters (or TADF). These recent developments triggered a renewed interest for the development of highly efficient fluorescent emitters for OLEDs. In this field, some of us pioneered the use  -conjugated phospholes 6 such A-B (Fig. ) as fluorescent emitters for both colored and white OLEDs, 7 as well as for the development of This P-based fluorophore takes advantage of an extended -system and a trigonal P-atom limiting the stacking in the solid-state and, thus, promoting an intense solidstate luminescence. Furthermore, the specific reactivity at the P-atom also allows fine-tuning the emission wavelength. Recently, the discovery of efficient metal-mediated synthesis of benzophospholes and the intense fluorescence associated to this core led to the preparation of new libraries of fluorophores. 10 Among them, Tang et al reported OLEDs based on C (Fig. ) which combine strong electron donor (triarylamine) to the benzophospholes electron acceptor. These devices displayed satisfying efficiency with EQE of 2%. In the present work, we report the synthesis of three new Benzophospholes-based fluorophores having an ethoxy substituent on the P-atom (compounds D in Fig 1) including different electron-donating groups, their full physico-chemical characterizations based on a joint experimental-theoretical approach and their insertion in OLEDs. In particular, we show that one compound reaches efficiency limit for a purely fluorescent emitter (EQE =5%), making it a very appealing derivative for further use in ultra-fast or organic lasers.