Authors: Mariarosa Cavallo, Erwan Bossavit, Sylvia Matzen, Thomas Maroutian, Rodolphe Alchaar, Tung Huu Dang, Adrien Khalili, Corentin Dabard, Huichen Zhang, Yoann Prado, Claire Abadie, James K Utterback, Jean Francois Dayen, Mathieu G. Silly, Pavel Dudin, Jose Avila, Emmanuel Lhuillier, Debora Pierucci
Published: 2023-05-15
Source: Full article
AbstractThe design of infrared nanocrystals‐based (NCs) photodiodes faces a major challenge related to the identification of barriers with a well‐suited band alignment or strategy to finely control the carrier density. Here, this study explores a general complementary approach where the carrier density control is achieved by coupling an NC layer to a ferroelectric material. The up‐and‐down change in ferroelectric polarization directly impacts the NC electronic structure, resulting in the formation of a lateral pn junction. This effect is uncovered directly using nano X‐ray photoemission spectroscopy, which shows a relative energy shift of 115 meV of the NC photoemission signal over the two different up‐ and down‐polarized ferroelectric regions, a shift as large as the open circuit value obtained in the diode stack. The performance of this pn junction reveals enhanced responsivity and reduced noise that lead to a factor 40 increase in the detectivity value.