2025/09/23 by Quinn Campbell, Campbell, Quinn T., Andrew Baczewski +6 · 1 voice
Engineering · Materials Science · Physics and Astronomy · #Advanced Materials and Semiconductor Technologies #Advancements in Semiconductor Devices and Circuit Design #Semiconductor materials and interfaces #Silicon and Solar Cell Technologies #Surface and Thin Film Phenomena
paper · doi:10.1088/1361-648x/ae4555
openalex publication_date 2026/02/12 · openalex created_date 2026/02/13 · openalex updated_date 2026/02/21
Silicon can be heavily doped with phosphorus in a single atomic layer (a<i>δ</i>layer), significantly altering the electronic structure of the conduction bands within the material. Recent progress has also made it possible to further dope silicon with acceptor-based<i>δ</i>layers using either boron or aluminum, making it feasible to create devices with interacting<i>δ</i>layers with opposite polarity. Using density functional theory, we calculate the electronic structure of a phosphorus-based<i>δ</i>layer interacting with a boron or aluminum<i>δ</i>layer, varying the distances between the<i>δ</i>layers. At separations 1 nm and smaller, the dopant potentials overlap and largely cancel each other out, leading to an electronic structure closely mimicking intrinsic silicon. At separations greater than 1 nm, the two<i>δ</i>layers behave independently of one another, with an equivalent electronic structure to a<i>p-n</i>diode with an intrinsic layer taking the place of the depletion region. One mechanism for charge transfer between<i>δ</i>layers at larger distances could be tunneling, where we see a tunneling probability exceeding what would be seen for a standard silicon 1.1 eV triangular barrier, indicating that the interaction between delta layers may enhance tunneling compared to a traditional junction.