A Vertical Phototransistor of Perovskite/Polymer Nano Heterojunction for Minimizing Ionic Defects

We report a vertical phototransistor based on nano heterojunction of perovskite nanocrystal and polymer semiconductor. The perovskite nanocrystals are of low-defect feature and the polymer spacing adjacent perovskite crystal helps the collection of photogenerated carriers. Compared with the pristine-film heterojunction method, our nano-heterojunction method reduces the dark current from 1.2×10 -5 A/cm 2 to 5.8×10 -8 A/cm 2 , improves the detectivity from 5.2×10 10 jones to 2.6×10 12 jones, and reduces the photocurrent decay by 95%. This also provides useful insights for pursuing high-performance and operational stable perovskite vertical phototransistors.