To further explore the EL performance of these near ultraviolet CPL materials, their doped OLEDs are fabricated and investigated. The device configuration is the same as that of the nondoped device, except using their doped films as EMLs. Taking S-BNPCN-o-CP as an example, the host is optimized between mCP and PPF at a doping concentration of 50 wt% S-BNPCN-o-CP in low-polar mCP host shows a bluer EL peak at 396 nm and a narrower FWHM of 46 nm relative to those in high-polar PPF host (EL peak = 404 nm; FWHM = 54 nm), but the ηext,max is increased from 7.1% in mCP host to 8.7% in PPF host (Supplementary Table ). Then, by increasing doping concentration from 10 to 80 wt% in PPF host, the doped devices of S-BNPCN-o-CP show red-shifted EL peaks from 388 nm (CIEx,y = 0.161, 0.032) to 406 nm (CIEx,y = 0.158, 0.037) (Table , Supplementary Fig. and Table ). And the ηext,maxs change little, with a peak value of 9.0% at 60 wt% doping concentration. Similar trends are observed for other S-enantiomers. The ηext,maxs and EL peaks of S-BNPCN-p-CP, S-BNPCN-o-TBCP and S-BNPCN-p-TBCP are 7.2% and 414 nm (CIEx,y = 0.157, 0.044), 9.1% and 420 nm (CIEx,y = 0.155, 0.052), and 6.7% and 428 nm (CIEx,y = 0.153, 0.066), respectively. These doped devices also hold great efficiency stability, with very small efficiency rolloffs 0-10.9% at 1000 cd m -2 luminance. Moreover, they exhibit good CP-EL signals as well, with |gEL| values of up to 2.02 × 10 -3 (Supplementary Fig. ). The R-enantiomers show similar EL results to the S-enantiomers (Supplementary Table ). In general, the ηext,maxs are increased while the |gEL| values become smaller in doped devices relative to nondoped devices, probably due to the irregular arrangement of molecules in blended system. These near ultraviolet CP-OLEDs actually have realized the state-of-the-art EL performances with apparent CP-EL signals in similar color regions to date. As discussed above, the achiral luminescent materials can acquire CP-PL signals via energy transfer from these near ultraviolet CPL materials. Encouraged by the impressive EL performance, it is envisioned that efficient CP-EL can be achieved for achiral luminescent materials by using these near ultraviolet CPL materials as hosts or sensitizers in OLEDs. As a proof concept, S-BNPCN-p-CP is adopted as the host and the typical TADF emitter (4CzTPNBu), MR-TADF emitter (BN3) and phosphorescence emitter (Ir(tptpy)2acac) are selected as the guests for EL investigation in device of ITO/HATCN (5 nm)/TAPC (50 nm)/TcTa (5 nm)/mCP (5 nm)/EML (20 nm)/PPF (5 nm)/TmPyPB (30 nm)/LiF (1 nm)/Al. The doped films of Ir(tptpy)2acac, 4CzTPNBu and BN3 in S-BNPCN-p-CP host at a concentration of 3 wt% work as EMLs. As shown in Fig. , the devices of Ir(tptpy)2acac, 4CzTPNBu and BN3 can be turned on at 2.7-2.9 V and radiate yellow-orange lights with EL peaks at 560, 558 and 572 nm and FWHMs of 60, 80 and 44 nm, respectively (Table ), which are in good agreement with their PL properties. The device of Ir(tptpy)2acac attains remarkable Lmax, maximum current efficiency (ηc,max), maximum power efficiency (ηP,max) and ηext,max of 209400 cd m -2 , 103.3 cd A -1 , 120.1 lm W -1 and 29.3%, respectively. The devices of 4CzTPNBu and BN3 also furnish excellent EL performances with Lmaxs of 132500 and 51410 cd m -2 , and ηext,maxs of 20.4% and 23.8%, respectively. The devices of Ir(tptpy)2acac and 4CzTPNBu possess small efficiency roll-offs of 7.1% and 13.7%, respectively, at 1000 cd m -2 luminance (Fig. and Supplementary Table ). Moreover, the devices of Ir(tptpy)2acac, respectively (Fig. ). R-BNPCN-p-CP also serves well as host for these achiral luminescent materials, providing comparable CP-EL performances (Table ).