Light Trapping in charge transfer states for improved organic photovoltaic performance

电荷转移状态下的光捕获可改善有机光伏性能

• 批准号: 1804690
• 负责人: Adam Moule
• 金额: $ 37.5万
• 依托单位: University of California-Davis
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-10-01 至 2022-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1804690&HistoricalAwards=false
• 关键词: Light; Trapping; charge; transfer; states

Photovoltaics (PVs) convert sunlight directly into electricity without any production of greenhouse gases. Most commercial PVs are made from silicon, which is expensive to process, heavy to transport, and brittle. This fundamental research project contributes to the development of PV devices that are made from organic materials that are low-cost, light-weight, and mechanically flexible. One issue for all PV devices is that the sunlight must be absorbed and not reflected from the surface for any angle of incidence on the surface. This problem has been addressed for silicon PV devices by roughening the front and back surfaces of the silicon in a specific pattern to cause the light to be absorbed into the silicon instead of being reflected back to space. This research project addresses a similar process to roughen the back surface of the organic PV layer to enhance absorption of light specifically in the near infrared portion of the solar spectrum, which contains a large proportion of the solar energy. Through this surface roughening process, the efficiency of organic PV devices will be increased, making them a better commercial option for clean energy production. The pattern will also make the organic PV absorb light more efficiently at high incidence angles, which is similar to sunlight in the morning and evening. Undergraduate and Ph.D. graduate students will be trained with research skills that are valued in the solar, polymer, and semiconducting industries. Student recruiting and outreach activities are designed to enhance inclusion of underrepresented minorities in research science.There is a critical need to engineer light‐trapping structures into organic photovoltaic (OPV) devices that can greatly increase the charge‐transfer (CT) state absorbance in the near infrared (NIR). The goal of this project is to enhance CT‐state absorbance in OPV devices using lateral light‐trapping structures. The overall objective is to develop a roll‐to‐roll (R2R) compatible optical patterning process to scribe lateral light‐trapping structures into OPV layers that can increase the external quantum efficiency (EQE) of CT‐state absorbance above 20% across a broad wavelength range. The central hypothesis of this project is that 700‐1000 nm 2D lateral patterning of the OPV layer combined with a thick active layer will achieve this goal of 20% EQE in the CT‐states. The rationale that underlies the research is to mimic light‐trapping structures used in inorganic thin‐film PV devices using solution processing methods that make OPV potentially both inexpensive and scalable. The University of California-Davis team brings expertise in OPV device fabrication, optical modeling, and conjugated polymer synthesis to the project. The project is structured into three aims. Aim 1: Create NIR light‐trapping structures using rapid optical processing. The working hypothesis is that deep light‐trapping structures will optimize waveguide modes below the excitonic band gap, leading to enhanced absorbance in the NIR range. Aim 2: Synthesize OPV materials with controlled solubility for optimized patterning. The pattern fidelity is maximized by high molecular weight and low dispersity polymers that are active donors for OPV applications. And Aim 3: Develop, test and model patterned OPV devices with record power conversion efficiency (PCE). The team will use large‐area solution patterning to fabricate patterned OPV devices with the most promising polymeric active materials. This fundamental research will enable a departure from flat OPV layers to focus on light capture in sub‐band gap states. The expected significance extends beyond the individual device efficiency as other researchers will be able to adopt the patterning method and industry will be able to expand its use to large area organic device applications.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

光伏（PVS）直接将阳光转化为电能，而无需生产温室气体。 大多数商业PV是由硅制成的，硅的处理价格很高，运输重量和脆性。这个基本的研究项目有助于开发由低成本，轻质和机械灵活的有机材料制成的PV设备。所有PV设备的一个问题是，必须吸收阳光，并且不会从表面上反射出表面的任何入射角。硅PV设备已经解决了该问题，通过以特定模式将硅的前表面和后表面粗糙，以使光被吸收到硅中，而不是反射回空间。该研究项目解决了一个类似的过程，以使有机PV层的背面粗糙表面，以增强在太阳能光谱的近红外部分中的光吸收，其中包含很大比例的太阳能。通过这个表面粗糙的过程，将提高有机光伏设备的效率，使其成为清洁能源生产的更好商业选择。该模式还将使有机光伏在高入射角上更有效地吸收光线，这与早晨和晚上相似。本科和博士学位研究生将接受在太阳能，聚合物和半导体行业中价值的研究技能培训。学生的招聘和外展活动旨在增强研究科学中代表性不足的少数群体的包含。迫切需要将Light＆Lights捕获到有机光伏（OPV）设备中，这些设备可以大大增加电荷＆＃8208; the Transver（ct）的状态（ct）在近乎基础的（nir）中。该项目的目的是使用横向光＆＃8208;捕获结构来增强OPV设备中的CT＆＃8208;状态吸光度。总体目的是将卷卷开发为兼容的光学图案过程，以涂抹横向光且捕获结构陷入OPV层中，从而可以增加跨宽波长范围以上20％的CT＆＃8208;状态吸收的外部量子效率（EQE）。该项目的中心假设是，OPV层的700＆＃8208; 1000 nm 2d侧向图案与较厚的活动层相结合将达到CT＆＃8208中20％EQE的目标。研究基础的基本原理是模仿无机薄薄薄膜PV设备中使用的诱捕结构，使用溶液处理方法，使OPV可能既便宜又可扩展。加利福尼亚大学戴维斯大学团队为该项目带来了OPV设备制造，光学建模和共轭聚合物合成方面的专业知识。该项目分为三个目标。 AIM 1：使用快速光学处理创建NIR Light＆＃8208;捕获结构。工作假设是，深光＆＃8208;捕获结构将优化示例带间隙下方的波导模式，从而在NIR范围内增强吸光度。目标2：合成具有控制溶解度的OPV材料，以优化模式。高分子重量和低分散性聚合物是OPV应用的活跃供体，使模式保真度最大化。 AIM 3：具有创纪录的电源转换效率（PCE）的开发，测试和模型的OPV设备。该团队将使用大型区域解决方案图案，以制造具有最有前途的聚合物活性材料的图案化OPV设备。这项基本研究将使从Flat OPV层出发，重点关注子隙状态下的灯光捕获。预期的意义超出了单个设备效率的范围，因为其他研究人员将能够采用模式方法，行业将能够将其用途扩展到大面积有机设备应用中。该奖项反映了NSF的法定任务，并被认为是通过基金会的知识分子优点和更广泛的审查标准来通过评估来获得支持的。