## 1 Introduction  
Organic light-emitting diodes (OLEDs) have drawn considerable commercialization attention as an efficient next generation of full-color flat-panel displays, as well as a solid-state lighting technology, because they have good flexibility, a fast response time, wide viewing angle, and low operation voltage [1; 2; 3; 4]. Furthermore, white OLEDs (WOLEDs) owing to their superb properties, such as their high contrast, light weight, high resolution, and large-scale manufacturing capability, have gained much attention recently [5; 6; 7]. To date, the current efficiency (CE) of WOLEDs has been greatly improved. However, organic materials emit light with a very broad spectrum and width due to the vibration sidebands and the strongly uneven broadening of electronic transitions, significantly lowering the device color purity. From this viewpoint, the use of an optical microcavity can effectively solve the poor color purity associated with broad emission characteristics [8; 9; 10]. The microcavity architecture is incorporated into OLEDs, and meanwhile, the emission of the device is coupled to the cavity mode, which greatly improves the emission directionality and the intensity of light, leading to high color purity [11; 12]. Planar microcavities consist of two mirrors that sandwich a kind of medium, of which the thickness is in the order of the wavelength. In OLED microcavities, the active layers of OLEDs are composed by the optimal medium between two mirrors [13]. The most common OLED microcavity architectures contain (i) two similar metal mirrors with different thicknesses, where one mirror is only partially reflective, while the other mirror is almost thoroughly reflective and (ii) one mirror serves as a dense dielectric distributed Bragg reflector (DBR), generally consisting of a periodic stack of SiO\({}_{2}\)/TiO\({}_{2}\) or SiO\({}_{2}\)/SiN as well as other mirror materials with a low work function metal [14; 15]. Recently, a great deal of attention has been paid to atomic layer deposition (ALD) as a potential advanced deposition method for thin-film fabrication. The ALD method relies on the precursor gases or vapors exhibiting an alternating pulse to the substrate surface as well as the subsequent surface reaction [16]. The inert gas among the precursor pulses can purify the reactor which shows a self-restriction development mechanism. Thus, conformal thin films possess a large area of precision [17]. Various multilayer structures develop in a straightforward manner [18]. Based on the proper adjustment of the experimental conditions, the experimental process is performed by continuous steps. Relying on the above conditions, the film grows stably and the layer thickness increases constantly in every deposition cycle. To demonstrate the spectrum with full wavelength as well as the high color rendering index (CRI), we created WOLEDs under the premise of sufficient complementary emission bands equipped with proper intensity. The study investigated high-efficiency WOLEDs on the basis of novel transparent DBR-containing alternative dielectric multilayers between inorganic and organic ZrO\({}_{2}\)/Zircone formed by the ALD method as a bottom dielectric mirror. Zircone as an organic material does have a problem of moisture sensitivity and is unstable. However, the first reason for choosing zircone is to consider the optical parameters of a DBR structure composed of zircone. The refractive indexes of Al\({}_{2}\)O\({}_{3}\), zircone, and ZrO\({}_{2}\) are 1.71, 1.46, and 2.13, respectively. The refractive index of Al\({}_{2}\)O\({}_{3}\) is higher than that of zircone. The refractive index difference between the two materials constituting the DBR structure in OLED devices is very important; the greater the difference of the refractive index (0.42 for Al\({}_{2}\)O\({}_{3}\)/ZrO\({}_{2}\); 0.67 for zircone/ZrO\({}_{2}\)) between the two materials, the easier it is to control the light-emitting spectrum of the device.