{"id":177584,"date":"2023-12-07T04:26:48","date_gmt":"2023-12-07T10:26:48","guid":{"rendered":"https:\/\/lifeboat.com\/blog\/2023\/12\/ultrahigh-gain-organic-transistors-based-on-van-der-waals-metal-barrier-interlayer-semiconductor-junction"},"modified":"2023-12-07T04:26:48","modified_gmt":"2023-12-07T10:26:48","slug":"ultrahigh-gain-organic-transistors-based-on-van-der-waals-metal-barrier-interlayer-semiconductor-junction","status":"publish","type":"post","link":"https:\/\/lifeboat.com\/blog\/2023\/12\/ultrahigh-gain-organic-transistors-based-on-van-der-waals-metal-barrier-interlayer-semiconductor-junction","title":{"rendered":"Ultrahigh-gain organic transistors based on van der Waals metal-barrier interlayer-semiconductor junction"},"content":{"rendered":"

<\/a><\/p>\n

To achieve high intrinsic gain (A<\/i>i<\/sub>) in OTFTs, it is necessary to enlarge output resistance (r<\/i>o<\/sub>) or transconductance (g<\/i>m<\/sub>) according to a typical formula of A<\/i>i<\/sub> = g<\/i>m<\/sub>r<\/i>o<\/sub>, which is very difficult for conventional OTFTs because of inherent device structure and operating mode limitations (11<\/i><\/a>, 12<\/i><\/a>). Recently, the \u201cSchottky barrier\u201d (SB) strategy based on metal-semiconductor junction (MS junction) has been adopted in TFTs to pursue high-gain and low-saturation voltage, including subthreshold SB-TFTs (11<\/i><\/a>, 12<\/i><\/a>, 15<\/i><\/a>, 16<\/i><\/a>) and source-gated transistors (17<\/i><\/a>, 18<\/i><\/a>). Unfortunately, the subthreshold transistors are limited in low and narrow subthreshold operating region rather than the normal ON-state region (namely, the normal voltage operating region in a typical TFT), which are difficult to be compatible with typical circuits. As far as we know, the ultrahigh-gain (1000) OTFTs operating in the ON-state region have not been previously reported. On the other hand, the state-of-the-art OTFTs above have mostly suffered from uncontrollable barriers owing to energy-level mismatches and a series of complex interface problems, such as Fermi-level pinning and interface chemical disorder (19<\/i><\/a>). In this case, considerable low-energy carriers are allowed to pass through the junction by thermionic field emission and tunneling models instead of thermionic emission model, which is not conducive to obtaining a high output resistance and high intrinsic gain. Most barrier heights in MS junction do not conform to the prediction value of Schottky-Mott rule. Theoretically, an ideal and high-quality barrier with thermionic emission model allows the rapid depletion of carriers at the source electrode, thus yielding ultrahigh gain, infinite output resistance, and low saturation voltage (11<\/i><\/a>, 12<\/i><\/a>). In addition, infinite output resistance at the saturation regime indicates that the output current is very stable and flat. This performance is helpful because only a single OTFT is used as a simplified current stabilizer in circuits without complex circuit design, which benefits low power and low cost in circuits. Therefore, it is necessary to develop a high-quality barrier strategy to modulate charge injection to meet the requirements of ultrahigh-gain OTFTs.<\/p>\n

Here, we demonstrate a metal-barrier interlayer-semiconductor (MBIS) junction to prepare high-performance MBIS-OTFT with an ultrahigh gain of ~104<\/sup> in the ON-state region, low saturation voltage, almost negligible hysteresis, and good stability. On the basis of low-energy processes and in situ surface oxidation technology, the high-quality van der Waals MBIS junction with wide-bandgap semiconductor (mainly Ga2<\/sub>O3<\/sub>) interlayer is achieved, allowing for an adjustable barrier height and thermionic emission properties. A series of in situ experiments and simulations revealed the relationship between the barriers and the device\u2019s performance. Furthermore, as demonstrations, a simplified current stabilizer and an ultrahigh-gain organic inverter are exhibited without complex circuit design.<\/p>\n","protected":false},"excerpt":{"rendered":"

To achieve high intrinsic gain (Ai) in OTFTs, it is necessary to enlarge output resistance (ro) or transconductance (gm) according to a typical formula of Ai = gmro, which is very difficult for conventional OTFTs because of inherent device structure and operating mode limitations (11, 12). Recently, the \u201cSchottky barrier\u201d (SB) strategy based on metal-semiconductor [\u2026]<\/p>\n","protected":false},"author":661,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[19,1523],"tags":[],"class_list":["post-177584","post","type-post","status-publish","format-standard","hentry","category-chemistry","category-computing"],"_links":{"self":[{"href":"https:\/\/lifeboat.com\/blog\/wp-json\/wp\/v2\/posts\/177584","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/lifeboat.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/lifeboat.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/lifeboat.com\/blog\/wp-json\/wp\/v2\/users\/661"}],"replies":[{"embeddable":true,"href":"https:\/\/lifeboat.com\/blog\/wp-json\/wp\/v2\/comments?post=177584"}],"version-history":[{"count":0,"href":"https:\/\/lifeboat.com\/blog\/wp-json\/wp\/v2\/posts\/177584\/revisions"}],"wp:attachment":[{"href":"https:\/\/lifeboat.com\/blog\/wp-json\/wp\/v2\/media?parent=177584"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/lifeboat.com\/blog\/wp-json\/wp\/v2\/categories?post=177584"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/lifeboat.com\/blog\/wp-json\/wp\/v2\/tags?post=177584"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}