High-Pressure Solvent Vapor Annealing with a Benign Solvent To Rapidly Enhance the Performance of Organic Photovoltaics

Jung, Buyoung,Kim, Kangmin,Eom, Yoomin,Kim, Woochul American Chemical Society 2015 ACS APPLIED MATERIALS & INTERFACES Vol.7 No.24

<P>A high-pressure solvent vapor annealing (HPSVA) treatment is suggested as an annealing process to rapidly achieve high-performance organic photovoltaics (OPVs); this process can be compatible with roll-to-roll processing methods and uses a benign solvent: acetone. Solvent vapor annealing can produce an advantageous vertical distribution in the active layer; however, conventional solvent vapor annealing is also time-consuming. To shorten the annealing time, high-pressure solvent vapor is exposed on the active layer of OPVs. Acetone is a nonsolvent for poly(3-hexylthiophene-2,5-diyl) (P3HT), but it can dissolve small amounts of 1-(3-methoxycarbonyl)-propyl-1,1-phenyl-(6,6)C<SUB>61</SUB> (PCBM). Acetone vapor molecules can penetrate into the active layer under high vapor pressure conditions to alter the morphology. HPSVA induces a PCBM-rich phase near the cathode and facilitates the transport of free charge carriers to the electrode. Although P3HT is not soluble in acetone, locally rearranged P3HT crystallites are generated. The performance of OPV films was enhanced after HPSVA; the film treated at 30 kPa for 10 s showed optimum performance. Additionally, this HPSVA method could be adapted for mass production because the temporary exposure of films to high-pressure acetone vapor in ambient conditions also improved performance.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/aamick/2015/aamick.2015.7.issue-24/acsami.5b01658/production/images/medium/am-2015-01658t_0007.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/am5b01658'>ACS Electronic Supporting Info</A></P>

Optimization of Long-Range Order in Solvent Vapor Annealed Poly(styrene)-<i>block</i>-poly(lactide) Thin Films for Nanolithography

Baruth, A.,Seo, Myungeun,Lin, Chun Hao,Walster, Kern,Shankar, Arjun,Hillmyer, Marc A.,Leighton, C. American Chemical Society 2014 ACS APPLIED MATERIALS & INTERFACES Vol.6 No.16

<P>Detailed experiments designed to optimize and understand the solvent vapor annealing of cylinder-forming poly(styrene)-<I>block</I>-poly(lactide) thin films for nanolithographic applications are reported. By combining climate-controlled solvent vapor annealing (including in situ probes of solvent concentration) with comparative small-angle X-ray scattering studies of solvent-swollen bulk polymers of identical composition, it is concluded that a narrow window of optimal solvent concentration occurs just on the ordered side of the order–disorder transition. In this window, the lateral correlation length of the hexagonally close-packed ordering, the defect density, and the cylinder orientation are simultaneously optimized, resulting in single-crystal-like ordering over 10 μm scales. The influences of polymer synthesis method, composition, molar mass, solvent vapor pressure, evaporation rate, and film thickness have all been assessed, confirming the generality of this behavior. Analogies to thermal annealing of elemental solids, in combination with an understanding of the effects of process parameters on annealing conditions, enable qualitative understanding of many of the key results and underscore the likely generality of the main conclusions. Pattern transfer via a Damascene-type approach verified the applicability for high-fidelity nanolithography, yielding large-area metal nanodot arrays with center-to-center spacing of 38 nm (diameter 19 nm). Finally, the predictive power of our findings was demonstrated by using small-angle X-ray scattering to predict optimal solvent annealing conditions for poly(styrene)-<I>block</I>-poly(lactide) films of low molar mass (18 kg mol<SUP>–1</SUP>). High-quality templates with cylinder center-to-center spacing of only 18 nm (diameter of 10 nm) were obtained. These comprehensive results have clear and important implications for optimization of pattern transfer templates and significantly advance the understanding of self-assembly in block copolymer thin films.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/aamick/2014/aamick.2014.6.issue-16/am503199d/production/images/medium/am-2014-03199d_0009.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/am503199d'>ACS Electronic Supporting Info</A></P>

Enhancing the Directed Self-assembly Kinetics of Block Copolymers Using Binary Solvent Mixtures

Park, Woon Ik,Choi, Young Joong,Yun, Je Moon,Hong, Suck Won,Jung, Yeon Sik,Kim, Kwang Ho American Chemical Society 2015 ACS APPLIED MATERIALS & INTERFACES Vol.7 No.46

<P>The rapid pattern formation of well-ordered block copolymer (BCP) nanostructures is practical for next-generation nanolithography applications. However, there remain critical hurdles to achieve the rapid self-assembly of BCPs with a high Flory–Huggins interaction parameter (χ), owing to their slow kinetics. In this article, we report that a binary solvent vapor annealing methodology can significantly accelerate the self-assembly kinetics of poly(dimethylsiloxane-<I>b</I>-styrene) (PDMS-<I>b</I>-PS) BCPs with a high-χ. In particular, we systemically analyzed the effects of the mixing ratio of a binary solvent composed of a PDMS-selective solvent (heptane) and a PS-selective solvent (toluene), showing an ultrafast self-assembly time (≤1 min) to obtain a well-ordered nanostructure. Moreover, we successfully accomplished extremely fast generation of sub-20 nm dot patterns within an annealing time of 10 s in a 300 nm-wide trench by means of binary solvent annealing. We believe that these results are also applicable to other solvent-based annealing systems of BCPs and that they will contribute to the realization of next-generation ultrafine lithography applications.</P><P>An extremely fast pattern generation (∼10 s) of PDMS-<I>b</I>-PS BCP with sub-20 nm was successfully accomplished by employing a binary solvent of PDMS-preferential (heptane) and PS-preferential (toluene). Furthermore, the use of binary solvent can also induce excellent tunability of the pattern size and period of BCPs.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/aamick/2015/aamick.2015.7.issue-46/acsami.5b08162/production/images/medium/am-2015-081629_0007.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/am5b08162'>ACS Electronic Supporting Info</A></P>

Solvent Vapor Annealing 처리를 통한 소분자 태양전지의 모폴로지 연구

김태양,안태규,박찬언 한국공업화학회 2018 한국공업화학회 연구논문 초록집 Vol.2018 No.0

소분자 태양전지에서 미세 단위의 모폴로지의 미세조정은 장치 성능을 높이는 데 중요한 매개 변수가 된다. 현재 연구에서, 활성막을 solvent vapor annealing (SVA)으로 처리하여 소분자 유기태양전지의 모폴로지를 제어하는데 초점을 맞추었다. 이 프로젝트에서, vapor annealing을 위해 소분자 p-DTS (FBTTh2) 2 : PC71BM 이형접합 막에 다른 solvent를 이용하여 디바이스를 제작하였다. 다른 용매 사용의 결과로 나노사이즈이 도메인 패킹 구조와 상분리가 일어났다. 우리는 활성막의 미세구조 모폴로지와 소자 성능 사이의 상관 관계를 보여 주었으며, 개선된 소자 성능을 나타내는 p-DTS (FBTTh2)2 : PC71BM 블렌드 시스템을 생성하는 SVA 조건을 발견했다. 우리는 이것을 XRD, 2D-GIWAXS으로 확인하였다.

Solvent Vapor Annealing Effects in Contact Resistances of Zone-cast Benzothienobenzothiophene (C₈-BTBT) Transistors

Kim, Chaewon,Jo, Anjae,Kim, Heeju,Kim, Miso,Lee, Jaegab,Lee, Mi Jung The Korean Ceramic Society 2016 한국세라믹학회지 Vol.53 No.4

Benzothienobenzothiophene ($C_8-BTBT$) is a soluble organic small molecule material with high crystallinity resulting from its strong self-organizing properties. In addition, the high mobility and easy fabrication of $C_8-BTBT$ make it very attractive in terms of organic thin-film transistors. In this work, we made $C_8-BTBT$ thin films by using the zone-casting method; we also used an organic solvent to treat the devices with solvent vapor annealing to improve the electrical properties. As a result, we confirmed improved mobility, threshold voltage, and subthreshold swing after solvent vapor annealing. To prove the effect of solvent vapor annealing, we used the simultaneous extraction model to extract the contact resistance from the current-voltage curve. We confirmed that the electrical properties improved with decreasing contact resistance.

Long-range single domain array of a 5-nm pattern of supramolecules via solvent annealing in a double-sandwich cell

권기옥 한국공업화학회 2020 한국공업화학회 연구논문 초록집 Vol.2020 No.-

In nanotechnology research, the generation of a single-grain nanostructure with a long-range lateral order is challenging. In this presentation, we report upon a new solvent-annealing method using a double-sandwich confinement to promote the formation of a large-area, single-domain array of supramolecular cylinders. Two key factors were found to be crucial in this process for generating highly-ordered supramolecular building blocks: i) the presence of a top coat during solvent evaporation and ii) the control of the solvent evaporation rate during the solvent evaporation step.

High Performance and Stable N-Channel Organic Field-Effect Transistors by Patterned Solvent-Vapor Annealing

Khim, Dongyoon,Baeg, Kang-Jun,Kim, Juhwan,Kang, Minji,Lee, Seung-Hoon,Chen, Zhihua,Facchetti, Antonio,Kim, Dong-Yu,Noh, Yong-Young American Chemical Society 2013 ACS APPLIED MATERIALS & INTERFACES Vol.5 No.21

<P>We report the fabrication of high-performance, printed, <I>n</I>-channel organic field-effect transistors (OFETs) based on an <I>N</I>,<I>N</I>-dialkyl-substituted-(1,7&1,6)-dicyanoperylene-3,4:9,10-bis(dicarboximide) derivative, PDI-RCN2, optimized by the solvent-vapor annealing (SVA) process. We performed a systematic study on the influence of solubility and the chemical structure of a solvent used for the SVA process on the ordering and orientation of PDI-RCN2 molecules in the thin film. The PDI-RCN2 film showed improved crystallinity under vapor annealing with the aliphatic 1,2-dichloroethane (DCE) as a marginal solvent. The <I>n</I>-type OFETs with DCE-vapor-annealed PDI-RCN2 show highly improved charge-carrier mobility of ∼0.5 cm<SUP>2</SUP> V<SUP>–1</SUP> s<SUP>–1</SUP> and higher stability under gate bias stress than the pristine OFETs. This large performance improvement was mainly attributed to increased crystallinity of the semiconductor thin film, enhancing π–π stacking. We also introduced a new method to pattern crystallinity of a certain region in the semiconducting film by selective exposure to the solvent vapor using a shadow mask. The crystal-patterned PDI-RCN2 OFETs exhibit decreased off-currents by ∼10× and improved gate bias stability by minimizing crosstalk, reducing leakage current between devices, and reducing the density of charge trap states of the organic semiconductor.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/aamick/2013/aamick.2013.5.issue-21/am4029075/production/images/medium/am-2013-029075_0008.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/am4029075'>ACS Electronic Supporting Info</A></P>

Evolution in crystal structure and electrical performance of thiophene-based polymer field effect transistors: A remarkable difference between thermal and solvent vapor annealing

Kang, S.J.,Song, S.,Liu, C.,Kim, D.Y.,Noh, Y.Y. Elsevier Science 2014 ORGANIC ELECTRONICS Vol.15 No.9

We report the various conformational structures of long pendant side-chains, and the effects of thermal and solvent vapor annealing (SVA) with the corresponding charge carrier mobilities of thiophene-based conjugated polymers, poly[5,5'-bis(3-dodecyl-2-thienyl)-2,2'-bithiophene] (PQT-12) and poly(4,4'-bis-decyloxymethylquaterthiophene) (POQT), by correlated study of their extraordinary polymorphic crystal structures. In substitution for alkyl chains in polythiophenes, ether alkyl chains induce a favorable non-covalent interaction between the oxygen and sulfur atoms and help the polymer chains planar with lower torsion angles between conjugated backbone units showing a reduced π-π stacking distance. However, the flexibility and conformational freedom with such long side-chains dominantly induce polymorphic crystallites from bent and extended side-chains. Especially, POQT exhibit two polymorphic crystallite phases in a similar ratio probably due to the increased freedom of ether alkyl chains. Therefore, the field effect mobility of POQT is decreased gradually with the increase of annealing temperature from 0.024 (at 80<SUP>o</SUP>C) to 3.96x10<SUP>-4</SUP>cm<SUP>2</SUP>/Vs (at 170<SUP>o</SUP>C). Contrary to the thermal annealing method, solvent-vapor-annealed POQT films show highly ordered and single-phase crystallites with edge-on orientation to the substrate, which ultimately provides an effectively improved charge carrier mobility from 0.023 (pristine) to 0.076cm<SUP>2</SUP>/Vs after adequate solvent vapor exposure.

용매 어닐링에 의한 박막에서 Polystyrene-Poly(1,4-butadiene) 블록공중합체의 모폴로지 전이

이동은(Dong Eun Lee),김응건(Eung Gun Kim),이동현(Dong Hyun Lee) 한국고분자학회 2012 폴리머 Vol.36 No.4

본 연구에서는 용매 증기 하에서 박막으로 제조된 polystyrene-poly(1,4-butadiene) 블록공중합체(PS-b-PBD)의 모폴로지 형성과 특성이 원자주사현미경(AFM)을 사용하여 연구되었다. 사이클로헥산으로만 용매 어닐링된 박막의 경우 폴리스티렌의 매트릭스 내부에 PBD가 미세상을 형성하는 perforated lamellae가 형성되었지만, n-헥산만으로 용매 어닐링 된 박막은 불규칙한 패턴만이 관측되었다. 그러나 사이클로헥산과 n-헥산의 혼합 용매를 사용하여 용 매 어닐링할 경우 기질에 수직으로 배향된 라멜라가 관측되었다. 이러한 모폴로지 전이는 혼합 용매의 혼합비에 의 해 조절되며 n-헥산의 양이 증가하면서 라멜라의 형성이 뚜렷이 관측되었다. 그러나 용매 어닐링에 사용된 혼합 용 매 중 n-헥산의 주요 성분이 될 경우 n-헥산의 PBD로의 용매 친화력에 의해 모폴로지 형성이 오히려 지연되는 것을 확인하였다. 이러한 사이클로헥산과 n-헥산의 혼합비에 따른 모폴로지 전이는 블록공중합체에 대한 두 용매들의 친화력과 관련 있으며, 이를 이해하기 위해 이들의 용해도 상수 및 Flory 상호인력 인자들이 고려되었다. 또한 본 연구로부터 얻어진 두 가지 모폴로지를 이용하여 실리카 나노 패턴의 제조를 위한 템플레이트로 활용하였다. Morphological characteristics and formation of symmetric polystyrene-block-poly (1,4-butadiene) copolymer (PS-b-PBD) in thin films upon solvent-annealing were investigated by using atomic force microscopy (AFM). The thin films solvent-annealed in cyclohexane revealed the perforated lamellae of poly (1,4-butadiene) in the matrix of polystyrene while those solvent-annealed in n-hexane exhibited highly disordered patterns. Interestingly, when the thin films of PS-b-PBD were solvent-annealed with binary mixtures of cyclohexane and n-hexane, the morphological transition from the perforated lameallae to the perpendicularly-oriented lamellae of poly(1,4-butadiene) could be induced by changing the mixing ratio of both solvents. We also demonstrated that after microdomians of poly (1, 4-butadiene) were successfully degraded by UV-O3, linear poly (dimethyl siloxane) chains were back-filled into the etched regions of the thin film and then converted to silica nano-objects by oxygen plasma treatments.

Solvent-vapor-annealed A-D-A-type semicrystalline Conjugated Small Molecules for Flexible Ambipolar Field-effect Transistors

김민제,이영웅,이유정,우한영,조정호 한국공업화학회 2019 한국공업화학회 연구논문 초록집 Vol.2019 No.0

This paper reports a series of A-D-A type small based on an oligothiophene- phenylene core with three different electron-accepting terminal groups -- VCN, RCN, and INCN, respectively -- for application to flexible ambipolar OFETs. All the P3T4-based OFETs exhibited ambipolar behavior with hole-dominant transport, and the OFET performances were strongly dependent on the terminal groups. The P3T4-INCN OFET exhibited the highest carrier mobility owing to the extended π-conjugation via the INCN moiety, which enhanced the intermolecular cofacial π-π stacking and generated an efficient carrier pathway in the transistor channel. Room temperature solvent vapor annealing resulted in a dramatic increase in the carrier mobility of the OFETs without causing any damage to a PEN substrate.