低维无机纳米材料在有机光伏与光探测器件中的应用研究
发布时间：2018-08-14 14:37
【摘要】：有机电子学在过去的60多年里一直是物理和化学领域的一大研究热点。由于具有成本低，质量轻和可制备大面积器件等优点，有机半导体非常有潜力成为无机半导体的替代材料。近年来，在有机半导体材料研究方面所取得的显著进展使有机光电器件的研制成为了可能，如有机发光二极管OLED、有机光伏器件OPV和有机光探测器件OPD等。尤其是OLED，如今已经在平板显示和室内照明方面达到了商业化应用的水平。但是目前OPV和OPD的性能与实用化的目标还有一定的距离，所以对于OPV和OPD的研究还有很长一段路要走。基于导电聚合物的光电器件作为有机光电器件中的一类，由于具有相对较高的性能和相对简单的溶液制备方法，近几年得到了非常广泛的研究。本论文的工作研究了低维无机纳米材料对于聚合物太阳能电池和有机/无机杂化紫外光探测器性能的影响。 在聚合物太阳能电池方面: 尽管目前新型的窄带隙聚合物给体材料层出不穷，但由于在450-600nm蓝绿光波段具有良好的吸收和较高的载流子迁移率，P3HT仍然是难以被取代的聚合物给体材料之一。若要从根本上提高P3HT/PCBM共混太阳能电池的能量转换效率，除了改善器件对入射光的利用率之外，必须突破材料自身固有的限制，，进一步提高电池器件的开路电压。 首先，采用NaF、YCl3·xH2O作为前驱体反应物，PVP作为表面活性剂，通过方法简便的溶剂热法合成了PVP包覆的NaYF4纳米颗粒。XRD数据显示，制备的纳米颗粒为立方相的β-NaYF4；SEM和TEM的表征结果表明，纳米颗粒的粒径分布在30-45nm之间。而且，可以清楚的观察到在纳米颗粒表面包覆有一层薄薄的PVP，使得NaYF4纳米颗粒能够溶于P3HT:PCBM的邻二氯苯混合溶液中。 然后，将制备好的NaYF4纳米颗粒按不同质量比掺入到P3HT:PCBM（1:1）的邻二氯苯混合溶液中配制成有源层溶液，并设计制作结构为ITO/TiO2/P3HT:PCBM:NaYF4/WO3/Ag的聚合物体异质结太阳能电池器件。当NaYF4纳米颗粒的质量分数为0.45wt%时，器件的性能达到最优，对应的光伏性能参数为：开路电压为0.62V，短路电流密度为9.63mA/cm2，填充因子为58.3%，能量转换效率为3.48%，与无纳米颗粒掺杂的器件相比，器件性能得到了明显的提升。 通过对掺入质量分数为0.75wt%的PVP且结构为ITO/TiO2/P3HT:PCBM:PVP/WO3/Ag的对比器件的研究发现，器件开路电压的提升主要是由包覆在NaYF4纳米颗粒表面的PVP引起。由于PVP能够与PCBM形成电荷转移复合物，而且PVP的HOMO能级（-5.93eV）比P3HT的HOMO能级（-5.21eV）更深，所以掺入PVP能够增大有源层的有效带隙，提高器件的内建电势，从而提高器件的开路电压。但是没有了NaYF4纳米颗粒载体，器件的填充因子明显变差。 通过对没有WO3空穴传输层的且结构为ITO/TiO2/P3HT:PCBM:NaYF4/Ag的对比器件的研究发现，纳米颗粒的引入可以改善有源层的内部形貌，有效地提高器件的填充因子。 通过对NaYF4颗粒掺杂的且器件结构为ITO/PEDOT:PSS/P3HT:PCBM:NaYF4/LiF/Al的正型结构对比器件的研究发现，PVP包覆的NaYF4纳米颗粒对基于P3HT:PCBM共混有源层的聚合物体异质结太阳能电池器件性能的提升是具有普遍性的，与器件是否为正型或者反型结构无关。 在有机/无机杂化紫外光探测器方面： 基于GaN、SiC或金刚石等无机宽禁带半导体材料的紫外光探测器一般需要通过金属有机化学气相沉积（MOCVD）或分子束外延（MBE）等复杂的制备方法来实现，导致探测器的生产成本较高。而且，无机半导体材料的禁带宽度调节起来也十分困难。相比之下，有机半导体材料及其与无机半导体材料形成的杂化材料为低成本、可大面积制备的紫外光探测器件的实现提供了相对简单的途径。另外，通过调整有机材料的化学结构可以比较容易地调节材料的吸收边位置，所以基于这类材料的紫外光探测器件在实现光响应的光谱选择特性时表现的更为灵活。 基于以上原因，本论文选取带隙较宽且具有空穴传导能力的聚乙烯基咔唑（PVK）作为电子给体材料，N型的TiO2二维纳米碗阵列（NBs）作为电子受体材料，并利用PVK/TiO2NBs异质结制成具有光谱选择特性的有机/无机杂化紫外光探测器。 首先，利用聚苯乙烯（PS）小球胶体模板法和溶胶-凝胶法在ITO衬底表面制备一层高度有序的TiO2二维纳米碗阵列。重点研究了TiO2溶胶溶液的浓度对纳米碗阵列形貌的影响，经过优化后制备得到的TiO2纳米碗结构的直径约为375nm,碗壁高度约为50nm，宽度约为100nm。由于TiO2的比表面积比较大，可以增加PVK和TiO2异质结的作用面积。 然后，在TiO2二维纳米碗阵列结构表面旋涂一层PVK薄膜，制成结构为ITO/TiO2NBs/PVK/WO3/Ag的有机/无机杂化紫外光探测器器件。ITO在作为电极的同时，还起到了短波长滤镜的作用，使器件表现出了一定程度的光谱选择特性。器件的具体性能参数为：器件的光响应度峰值位于330nm处，十分靠近UV-B波段（280-320nm），响应波长范围290-375nm，半峰宽约为38.5nm，且在光照强度为144mWcm-2、波长为330nm的紫外光照射条件下，偏压为-5V时，响应度峰值约为8.14A/W。 通过对TiO2二维纳米碗阵列正面和背面的反射光谱进行研究发现，纳米碗阵列结构正面在330nm纳米处存在一个反射峰，而背面在375nm处存在一个反射峰，这对整个器件的波长选择特性具有积极的作用。
[Abstract]:Organic electronics has been a research hotspot in the field of physics and chemistry for more than 60 years. Due to its low cost, light weight and large-area fabrication, organic semiconductors have great potential to become substitutes for inorganic semiconductors. In recent years, remarkable progress has been made in the research of organic semiconductors. Organic optoelectronic devices, such as OLED, OPV and OPD, have become possible. Especially OLED, now it has reached the level of commercial application in flat panel display and indoor lighting. There is still a long way to go for the study of OPV and OPD. As a kind of organic optoelectronic devices, conductive polymer-based optoelectronic devices have been widely studied in recent years due to their relatively high performance and relatively simple solution preparation methods. Effects of solar cells and organic / inorganic hybrid UV detectors.
In terms of polymer solar cells:
Although new narrow band gap polymer donors are emerging in endlessly, P3HT is still one of the most difficult polymer donors because of its good absorption and high carrier mobility in 450-600 nm blue-green light band. In addition to the utilization of incident light, the device must break through the inherent limitations of the material itself and further increase the open circuit voltage of the battery device.
Firstly, NaYF4 nanoparticles coated with PVP were synthesized by a simple solvothermal method using NaF, YCl3 xH2O as precursor reactants and PVP as surfactant. XRD data showed that the prepared nanoparticles were cubic phase beta-NaYF4. SEM and TEM characterization results showed that the nanoparticles were between 30 and 45 nm in diameter. It was clearly observed that a thin layer of PVP was coated on the surface of the nanoparticles, enabling NaYF4 nanoparticles to dissolve in the mixed solution of 3 HT: PCBM and o-dichlorobenzene.
Then, the prepared NaYF4 nanoparticles were mixed into the mixed solution of P3HT: PCBM (1:1) and o-dichlorobenzene to prepare the active layer solution. The polymer heterojunction solar cell device with ITO / TiO2 / P3HT: PCBM: NaYF4 / WO3 / Ag structure was designed and fabricated. When the mass fraction of NaYF4 nanoparticles was 0.45wt%, the device properties were studied. The corresponding photovoltaic performance parameters are: open-circuit voltage is 0.62V, short-circuit current density is 9.63mA/cm2, filling factor is 58.3%, energy conversion efficiency is 3.48%. Compared with the device without nano-particle doping, the device performance has been significantly improved.
It is found that the increase of the open circuit voltage is mainly caused by the PVP coated on the surface of NaYF4 nanoparticles. PVP can form charge transfer complex with PCBM, and the HOMO level of PVP (-5.93eV) is higher than that of P3HT. Stage (-5.21 eV) is deeper, so the effective band gap of active layer can be increased by adding PVP, and the built-in potential of the device can be increased, thus the open circuit voltage of the device can be increased.
The comparison device without WO3 hole transport layer and ITO/TiO2/P3HT:PCBM:NaYF4/Ag structure was studied. It was found that the introduction of nanoparticles could improve the internal morphology of the active layer and effectively improve the filling factor of the device.
It is found that PVP-coated NaYF4 nanoparticles can improve the performance of polymer heterojunction solar cell devices based on P3HT:PCBM blend active layer by doping with NaYF4 particles and the device structure is ITO/PEDOT:PSS/P3HT:PCBM:NaYF4/LiF/Al. The inverse structure is independent.
In organic / inorganic hybrid UV detectors,
Ultraviolet photodetectors based on GaN, SiC or diamond have to be fabricated by complex methods such as metal organic chemical vapor deposition (MOCVD) or molecular beam epitaxy (MBE), which results in high production cost. Moreover, it is difficult to adjust the band gap of inorganic semiconductor materials. In contrast, organic semiconductors and their hybrid materials with inorganic semiconductors provide a relatively simple way to achieve low-cost, large-area fabrication of ultraviolet detectors. In addition, by adjusting the chemical structure of organic materials, it is relatively easy to adjust the absorption edge position of materials, so based on such materials. The UV detector of the material is more flexible in achieving spectral response characteristics of light response.
Based on the above reasons, PVK with wide band gap and hole conduction ability is selected as electron donor material, N-type titanium dioxide two-dimensional nano-bowl array (NBs) as electron acceptor material, and PVK/TiO2NBs heterojunction is used to fabricate organic/inorganic hybrid UV photodetectors with spectral selectivity.
Firstly, a highly ordered two-dimensional nano-bowl array of titanium dioxide was prepared on ITO substrate by polystyrene (PS) sphere colloid template method and sol-gel method. The width is about 100 nm and the specific surface area of TiO2 is larger than that of PVK.
Then, a layer of PVK film was spin-coated on the surface of the two-dimensional nano-bowl array of titanium dioxide, and a hybrid organic/inorganic ultraviolet detector with ITO/TiO2NBs/PVK/WO3/Ag structure was fabricated. Number: The peak of the photoresponsivity of the device is located at 330 nm, very close to the UV-B band (280-320 nm), the response wavelength range is 290-375 nm, the half-peak width is about 38.5 nm, and the response peak value is about 8.14 A/W when the illumination intensity is 144 mWcm-2, the wavelength is 330 nm, and the bias voltage is - 5 V.
It is found that there is a reflection peak at 330 nm on the front of the nano-bowl array and a reflection peak at 375 nm on the back of the nano-bowl array, which has a positive effect on the wavelength selectivity of the whole device.
【学位授予单位】：吉林大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：TB383.1;TM914.4
本文编号：2183171
[Abstract]:Organic electronics has been a research hotspot in the field of physics and chemistry for more than 60 years. Due to its low cost, light weight and large-area fabrication, organic semiconductors have great potential to become substitutes for inorganic semiconductors. In recent years, remarkable progress has been made in the research of organic semiconductors. Organic optoelectronic devices, such as OLED, OPV and OPD, have become possible. Especially OLED, now it has reached the level of commercial application in flat panel display and indoor lighting. There is still a long way to go for the study of OPV and OPD. As a kind of organic optoelectronic devices, conductive polymer-based optoelectronic devices have been widely studied in recent years due to their relatively high performance and relatively simple solution preparation methods. Effects of solar cells and organic / inorganic hybrid UV detectors.
In terms of polymer solar cells:
Although new narrow band gap polymer donors are emerging in endlessly, P3HT is still one of the most difficult polymer donors because of its good absorption and high carrier mobility in 450-600 nm blue-green light band. In addition to the utilization of incident light, the device must break through the inherent limitations of the material itself and further increase the open circuit voltage of the battery device.
Firstly, NaYF4 nanoparticles coated with PVP were synthesized by a simple solvothermal method using NaF, YCl3 xH2O as precursor reactants and PVP as surfactant. XRD data showed that the prepared nanoparticles were cubic phase beta-NaYF4. SEM and TEM characterization results showed that the nanoparticles were between 30 and 45 nm in diameter. It was clearly observed that a thin layer of PVP was coated on the surface of the nanoparticles, enabling NaYF4 nanoparticles to dissolve in the mixed solution of 3 HT: PCBM and o-dichlorobenzene.
Then, the prepared NaYF4 nanoparticles were mixed into the mixed solution of P3HT: PCBM (1:1) and o-dichlorobenzene to prepare the active layer solution. The polymer heterojunction solar cell device with ITO / TiO2 / P3HT: PCBM: NaYF4 / WO3 / Ag structure was designed and fabricated. When the mass fraction of NaYF4 nanoparticles was 0.45wt%, the device properties were studied. The corresponding photovoltaic performance parameters are: open-circuit voltage is 0.62V, short-circuit current density is 9.63mA/cm2, filling factor is 58.3%, energy conversion efficiency is 3.48%. Compared with the device without nano-particle doping, the device performance has been significantly improved.
It is found that the increase of the open circuit voltage is mainly caused by the PVP coated on the surface of NaYF4 nanoparticles. PVP can form charge transfer complex with PCBM, and the HOMO level of PVP (-5.93eV) is higher than that of P3HT. Stage (-5.21 eV) is deeper, so the effective band gap of active layer can be increased by adding PVP, and the built-in potential of the device can be increased, thus the open circuit voltage of the device can be increased.
The comparison device without WO3 hole transport layer and ITO/TiO2/P3HT:PCBM:NaYF4/Ag structure was studied. It was found that the introduction of nanoparticles could improve the internal morphology of the active layer and effectively improve the filling factor of the device.
It is found that PVP-coated NaYF4 nanoparticles can improve the performance of polymer heterojunction solar cell devices based on P3HT:PCBM blend active layer by doping with NaYF4 particles and the device structure is ITO/PEDOT:PSS/P3HT:PCBM:NaYF4/LiF/Al. The inverse structure is independent.
In organic / inorganic hybrid UV detectors,
Ultraviolet photodetectors based on GaN, SiC or diamond have to be fabricated by complex methods such as metal organic chemical vapor deposition (MOCVD) or molecular beam epitaxy (MBE), which results in high production cost. Moreover, it is difficult to adjust the band gap of inorganic semiconductor materials. In contrast, organic semiconductors and their hybrid materials with inorganic semiconductors provide a relatively simple way to achieve low-cost, large-area fabrication of ultraviolet detectors. In addition, by adjusting the chemical structure of organic materials, it is relatively easy to adjust the absorption edge position of materials, so based on such materials. The UV detector of the material is more flexible in achieving spectral response characteristics of light response.
Based on the above reasons, PVK with wide band gap and hole conduction ability is selected as electron donor material, N-type titanium dioxide two-dimensional nano-bowl array (NBs) as electron acceptor material, and PVK/TiO2NBs heterojunction is used to fabricate organic/inorganic hybrid UV photodetectors with spectral selectivity.
Firstly, a highly ordered two-dimensional nano-bowl array of titanium dioxide was prepared on ITO substrate by polystyrene (PS) sphere colloid template method and sol-gel method. The width is about 100 nm and the specific surface area of TiO2 is larger than that of PVK.
Then, a layer of PVK film was spin-coated on the surface of the two-dimensional nano-bowl array of titanium dioxide, and a hybrid organic/inorganic ultraviolet detector with ITO/TiO2NBs/PVK/WO3/Ag structure was fabricated. Number: The peak of the photoresponsivity of the device is located at 330 nm, very close to the UV-B band (280-320 nm), the response wavelength range is 290-375 nm, the half-peak width is about 38.5 nm, and the response peak value is about 8.14 A/W when the illumination intensity is 144 mWcm-2, the wavelength is 330 nm, and the bias voltage is - 5 V.
It is found that there is a reflection peak at 330 nm on the front of the nano-bowl array and a reflection peak at 375 nm on the back of the nano-bowl array, which has a positive effect on the wavelength selectivity of the whole device.
【学位授予单位】：吉林大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：TB383.1;TM914.4
【参考文献】
相关博士学位论文 前1条
1 陶晨;反型体异质结聚合物太阳能电池的研究[D];吉林大学;2010年
本文编号：2183171
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