Bio-Inspired Learning in N ₂ -Doped SnO ₂ -Based Photonic Memristor Synapse

A N<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> doped (3.19 atomic %) SnO<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub>-based Pt/SnO<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub>:N<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub>/Pt memristor photonic synapse with interdigitated contacts (IDC) has been demonstrated here, which shows optical long-term potentiation and electrical depression (also LTP) characteristics. N<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> doping was optimized in this regard so that SnO<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> absorption edge could be obtained at λ =365nm and percentage of oxygen vacancies could be tailored to 16.35% for an optimum resistance contrast. Paired pulse facilitation (PPF) characterization on the fabricated memristor revealed associative learning ability, which was further characterized within the context of hypothetical Pavlov’s experiment through providing voltage and light pulses as conditioned and unconditioned stimuli to the memristor.