Iron Pyrite / a super absorber for PV solar energy

黄铁矿/光伏太阳能超级吸收剂

• 批准号: EP/F061390/1
• 负责人: Stuart Irvine
• 金额: $ 22.66万
• 依托单位: Glyndwr University
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2008
• 资助国家: 英国
• 起止时间: 2008 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=EP%2FF061390%2F1
• 关键词: Iron; Pyrite; super; absorber; PV

Reducing the materials costs and improving efficiencies for solar cells is an ongoing research area that has global interest. Currently, crystalline silicon cells account for 90% of the PV market. Whilst conversion efficiency levels are considered high, the production costs for crystalline silicon are significantly higher than for thin film materials. However, the current conversion efficiency for thin film PV is significantly less than for crystalline silicon hence reducing some of the cost advantage. There is considerable scope for thin film solar cell development, where improvements in cell efficiency can be made with improved materials and device structures. One improvement that will lead to better conversion efficiency is to increase the photon absorption into the cell, close to the junction. A promising candidate for application as an absorbing layer in a photovoltaic device is iron pyrite (FeS2). The high absorption coefficient of FeS2 is consistent with its high density of states in the conduction band. The relatively small band gap allows for visible and infrared wavelengths to be absorbed, and the combination of direct and indirect band gap transitions contribute to its high absorption coefficient. However, this has not yet been turned into an efficient PV device. Iron pyrite has the potential to become a very important material for very large scale manufacture of thin film PV modules where the elemental constituents are very abundant and combines with the much smaller amounts of absorber material needed (thickness of 100 nm or less) making this a very sustainable and low cost material.This feasibility proposal will investigate the promising MOCVD route to deposit very thin films of FeS2 and introduce these into a novel p-i-n structure, taking advantage of the recent success with the MOCVD CdTe PV devices on the PV Supergen project. This structure will take advantage of the super-absorption characteristics to sandwich a very thin film absorber between n-type CdS and p-type CdTe:As layers. The purpose will be to show that high efficiency PV devices can be made from FeS2 where the photo-generated carriers are collected by drift in the electric field rather than by diffusion, thus reducing carrier loss. As part of the feasibility it is intended to scope future developments by replacing the CdS and CdTe n-type and p-type layers with more sustainable materials.

降低太阳能电池的材料成本和提高效率是一个正在进行的研究领域，具有全球利益。目前，晶体硅电池占光伏市场的90%。虽然转换效率水平被认为是高的，但是晶体硅的生产成本显著高于薄膜材料。然而，薄膜PV的电流转换效率明显低于晶体硅，因此降低了一些成本优势。薄膜太阳能电池的开发有相当大的空间，其中可以利用改进的材料和器件结构来提高电池效率。将导致更好的转换效率的一个改进是增加进入电池的光子吸收，靠近结。在光伏器件中用作吸收层的有希望的候选物是黄铁矿（FeS 2）。FeS 2的高吸收系数与其在导带中的高态密度一致。相对较小的带隙允许吸收可见光和红外波长，并且直接和间接带隙跃迁的组合有助于其高吸收系数。然而，这还没有变成有效的PV装置。黄铁矿有潜力成为非常重要的材料，用于非常大规模地制造薄膜PV模块，其中元素成分非常丰富，并且与所需的少量吸收剂材料结合（厚度为100 nm或更小）使其成为一种非常可持续和低成本的材料。该可行性提案将研究有前途的MOCVD路线，以存款非常薄的FeS 2薄膜，利用最近在PV Supergen项目上成功开发的MOCVD CdTe PV器件，将这些材料引入到新型p-i-n结构中。这种结构将利用超吸收特性，在n型CdS和p型CdTe：As层之间夹入非常薄的薄膜吸收体。目的是表明，高效率的光伏器件可以由FeS 2制成，其中光生载流子通过电场中的漂移而不是通过扩散来收集，从而减少载流子损耗。作为可行性的一部分，它旨在通过用更可持续的材料取代CdS和CdTe n型和p型层来确定未来的发展范围。