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
${1}.{2}\times {10} ^{-{5}}$
A/cm2 to
${5}.{8}\times {10} ^{-{8}}$
A/cm2, improves the detectivity from
${5}.{2}\times {10} ^{{10}}$
jones to
${2}.{6}\times {10} ^{{12}}$
jones, and reduces the photocurrent decay by 95%. This also provides useful insights for pursuing high-performance and operational stable perovskite vertical phototransistors.