## 4 Discussion  
The idea of creating photoconversion films appeared more than thirty years ago [36]. At the first stage, films were created based on polyethylene and organic fluorophores. These films had a short life, the fluorophores degraded rather quickly. The next stage was the use of compounds based on rare earth elements as fluorophores [37]. These fluorophores were fairly persistent, but had a low quantum yield. A new generation of photoconversion films for greenhouses is created on the basis of nanoscale fluorophores and complex dyes [38; 39; 40]. There are also special films; for example, our team has developed a film in which two nanoscale fluorophores and gold nanoparticles are present as an additive. The film was developed for arctic conditions and allows not only photoconversion UV quantum to red quantum, but also the conversion of a part of the green quantum (little used by  
Figure 4: Influence of a photoconversion fluoropolymer film on the growth and development of plants of different species. **(a)** Effect of photoconversion polymer film on the leaf size of cucumber (_Cucumis sativus_), pumpkin (_Cucurbita pepo_), pepper (_Capsicum annuum_ L.), tomato (_Solanum loyopersicum_) plants. Control values are normalized. Data are presented as median with 95% confidence interval (box). The range is shown in the form of a whiskers. Statistically significant differences between control group and other groups (Mann-Whitney \(U\) test, \(p<0.05\)) are marked by asterisks. **(b)** Dynamics of changes in the leaf area of control tomato plants and tomato plants grown under a photoconversion polymer film. Statistically significant differences between control group and other groups (Mann-Whitney \(U\) test, \(p<0.05\)) are marked by asterisks.  
plants) into heat [27]. In this work, quantum dots are synthesized with a quantum yield of about 20%, with emission in the blue (460 nm) and red (650 nm) spectral regions (Figures 1 and 2). Usually, most research uses fluorophores with an emission around 630 nm. We know that the photosystems of higher plants operate at wavelengths close to 675-695 nm and 660-683 nm. The more the wavelength of light differs from these values, the less efficient is the absorption of light quanta. For example, green quanta are absorbed significantly less efficiently than red ones. In this work, using the Pu & Hsu method [28], we were able to make a fluorophore with an emission of 650 nm (20 nm closer to photosystems optimum).  
It has been found that photoconversion films accelerate plant growth in the early stages of growth (Figures 3 and 4). Most of the works known to us also investigate the effect of converted radiation on the growth rate of plants in the early stages. Moreover, the effect of the converted sunlight on the rate of photosynthesis and various physiological parameters of plants is usually studied [41]. This manuscript focuses on all stages of plant development, including the fruiting stage. We have shown that the film developed by us allows us to increase the yield of plants (on average, each tomato bush brings more yield) (Figure 5). This is important not only from the point of view of technology and fundamental science, but can also have significant applied value.