###### Abstract  
In this paper, we present an approach that makes it possible to describe, from unified physical considerations, the influence of rotation-angle and concentration disorder on the density of electronic states of two-layer twisted graphene. The electron relaxation time and the density of electronic states near the Fermi level are calculated by considering the multiple elastic scattering of electrons by impurities and structural inhomogeneities of the short-range order type. An analysis is presented of the change in the contributions to the density of electronic states from electron scattering on foreign atoms with variations in the defectiveness of the structure, impurity concentration, temperature, and the external electric field magnitude. It is shown that the formation of short-range order areas by foreign atoms in the first coordination sphere relative to the surface of the material can lead to the opening of a gap in the density of electronic states of twisted graphene. Point defects and short-range order regions formed by foreign atoms in the second coordination sphere lead to metallization of twisted graphene. twisted graphene; structure; short-range order; twist-angle disorder; density of electronic states +
Footnote †: journal: Applied Physics Letters  
**Acticle**  
**Influence of Twist-Angle and Concentration Disorder on the Density of Electronic States of Twisted Graphene. _Appl. Sci._**2022**, 12, 4109. [[https://doi.org/10.3390/appl2094109](https://doi.org/10.3390/appl2094109)]([https://doi.org/10.3390/appl2094109](https://doi.org/10.3390/appl2094109))  
**Academic Editors: [PERSON] and [PERSON]**  
Received: 29 March 2022  
Accepted: 16 April 2022  
Published: 19 April 2022  
**Published: 2022**  
layers. It has been experimentally established that electron localization can induce both insulating [14] and superconducting [15] behavior of electronic properties at certain angles. Despite numerous studies of the electronic structure of tBLG [10; 11; 12; 13; 14; 15], the effect of the formation of Moire structures on the change in the electron transport properties has not been studied enough. Previous studies have shown that additional disorder can be formed due to interaction with various types of substrates, thermal post-processing, functionalization, etc. [16; 17; 18; 19]. Such a disorder, as well as the rotation of graphene layers, affects the behavior of the electrons in tBLG. Experimental and theoretical studies of tBLG have revealed that foreign atoms on the surface are distributed unevenly. There are 11 different positions of adsorbed atoms on the tBLG surface depending on the rotation angle [20; 21]. [PERSON] et al. [21; 22] attribute this to the fact that tBLG supercells contain high symmetry areas (AA, AB (BA), and fullerene-like framework structures), which are adsorption centers in the material. For twist angles \(\theta\) in the range from \(0^{\circ}\) to \(16^{\circ}\), there are domains with AA or AB(BA) stacking. Outside this range, the adsorption centers are similar to the frame fullerene-like structures that appear at \(\theta=30^{\circ}\). Density functional calculations [21] showed that the position of adsorbate atoms is determined by the type of stacking at a particular tBLG point. Depending on the concentration of foreign atoms during functionalization and the doping of tBLG with a substrate, the structural defects of the material can be point or form areas of a short-range and long-range order. This is confirmed by SEM and TEM images, as well as changes in the intensity smearing and position of the D peak of various processed tBLGs investigated by Raman spectroscopy [23; 24]. An external field also makes a significant contribution to the electronic structure of tBLG. It was found [25; 26] that the gap in the density of electronic states (DOS) of bilayer graphene can open only in the presence of an external field. The appearance of a gap and its width are determined by the external field value and the impurity concentration in tBLG samples. [PERSON] et al.