非晶硅薄膜太陽電池陷光結(jié)構(gòu)的模擬與設(shè)計
發(fā)布時間：2019-07-02 12:27
【摘要】：與第一代晶體硅太陽電池相比，非晶硅薄膜太陽電池具有節(jié)省原材料、制備工藝簡單，成本低廉等優(yōu)勢。但是，由于薄膜材料的缺陷態(tài)密度較高，厚的非晶硅層雖然能夠較好的吸收入射光，但是加劇了復(fù)合，載流子的收集效率下降，因此，一般要求電池光吸收層的厚度小于其少數(shù)載流子的有效擴散長度；而過薄的非晶硅層顯然不能充分吸收入射光，尤其是對帶隙附近的光的吸收率很低，同樣限制了電池的短路電流和光電轉(zhuǎn)換效率。為了解決上述矛盾，必須為電池設(shè)計有效的陷光結(jié)構(gòu)，在電池光吸收層的物理厚度不變的情況下，大大增加其光學(xué)厚度，這種電薄光厚的電池可以在保證載流子收集效率的同時，有效改善電池的光吸收。 本學(xué)位論文首先介紹了常用的非晶硅薄膜陷光技術(shù)，并重點綜述了金屬納米結(jié)構(gòu)表面產(chǎn)生的表面等離激元(Surface Plasmon，簡稱SP)在太陽電池陷光中的應(yīng)用。在此基礎(chǔ)上，分別將一維或二維周期性分布金屬納米結(jié)構(gòu)(即金屬納米光柵)引入非晶硅薄膜電池的前表面或后表面，并結(jié)合傳統(tǒng)的陷光技術(shù)，如減反膜、表面織構(gòu)等，為非晶硅薄膜電池設(shè)計出了多種陷光結(jié)構(gòu)。論文采用基于有限元法的COMSOL數(shù)值模擬軟件，模擬了不同陷光結(jié)構(gòu)太陽電池的光吸收。通過分析電池在不同波段的光子吸收率、吸收光譜、光吸收層中的電磁場分布以及金屬納米顆粒散射截面等，對上述幾種陷光結(jié)構(gòu)進行了優(yōu)化，闡述了其陷光機理。本文取得的主要研究成果如下： (1)在非晶硅薄膜太陽電池前表面設(shè)計一維Ag納米光柵：在TM波垂直入射的情況下，前表面有一維Ag納米光柵的電池在短波段的光子吸收率較參考電池有一定下降，但在中長波段的光子吸收率則有較大幅度地提高；當(dāng)光柵截面半徑R=50nm，周期P=350nm時，電池總的光吸收較參考電池提高了29.5%。然而，在TE波入射下，由于Ag光柵表面不能產(chǎn)生表面等離激元，且Ag光柵本身對入射光的有一定的吸收和反射，導(dǎo)致電池在混合波入射時，整個入射光譜(300~800nm)范圍內(nèi)吸收的光子數(shù)僅為參考電池的92%。也就是說，在前表面引入一維Ag納米光柵后，非晶硅薄膜太陽電池的光吸收反而降低�；谏鲜瞿M結(jié)果，我們認為：在太陽電池陷光設(shè)計中，，不宜將一維金屬納米光柵置于電池前表面。 (2)復(fù)合陷光結(jié)構(gòu)的設(shè)計與優(yōu)化：在Ag背電極與硅薄膜之間制備一維金屬納米光柵,并通過保形生長在電池前表面沉積織構(gòu)的減反膜，該復(fù)合陷光結(jié)構(gòu)可獲得較好的陷光效果。當(dāng)背表面一維金屬納米光柵的橫截面為三角形時，填充因子FF=0.5的光柵的陷光效果優(yōu)于FF=1的光柵，與Al光柵相比，Ag光柵的效果更佳。當(dāng)光柵橫截面頂角為θ=80°，面積S=18750nm2時，電池在AM1.5太陽光譜垂直入射下總的光吸收較參考電池提高率Eabs達96%；當(dāng)背表面一維Ag納米光柵的橫截面為矩形時，矩形高度H=90nm，寬度W=180nm，光柵的周期P=600nm時，Eabs達到最大值103%。上述復(fù)合陷光結(jié)構(gòu)設(shè)計均可在寬光譜范圍內(nèi)提高非晶硅薄膜電池的光吸收，其中，中短波段光吸收的改善主要歸因于前表面減反膜和表面織構(gòu)的貢獻，而長波段光子吸收率的提高則是Ag納米光柵表面等離激元和波導(dǎo)模共同作用的結(jié)果。另外，上述復(fù)合陷光結(jié)構(gòu)設(shè)計還較大地改善了非晶硅薄膜電池對太陽光入射角度的敏感性。 (3)周期性分布的Ag納米顆粒對非晶硅薄膜電池光吸收的影響：將Ag納米顆粒置于電池前表面時，在平面波垂直入射下，電池在中長波段的光子吸收率較參考電池有明顯提高；其中，大顆粒在大的分布周期下陷光效果較好，當(dāng)Ag納米顆粒半徑R取110nm，周期P取500nm時，Eabs達到最大值49%。將Ag納米顆粒分別置于電池前后表面同一位置時，電池的Eabs可提升至55%。但是，該陷光結(jié)構(gòu)電池對入射光的角度變化較敏感，要取得良好的陷光效果，應(yīng)保持入射角度在30度以內(nèi)。
[Abstract]:Compared with the first-generation crystalline silicon solar cell, the amorphous silicon thin-film solar cell has the advantages of saving raw materials, simple preparation process, low cost and the like. However, because the defect state density of the thin film material is high, the thick amorphous silicon layer can absorb the incident light well, but the recombination and the collector efficiency of the carriers are reduced, and therefore, the thickness of the light absorbing layer of the battery is generally required to be less than the effective diffusion length of the minority carriers; And the over-thin amorphous silicon layer obviously cannot fully absorb the incident light, especially the absorption rate of the light in the vicinity of the band gap is low, and the short-circuit current and the photoelectric conversion efficiency of the battery are also limited. In order to solve the above-mentioned contradiction, it is necessary to design an effective light-trapping structure for the battery, greatly increase the optical thickness of the light-absorbing layer of the battery under the condition that the physical thickness of the light-absorbing layer of the battery is not changed, and the light absorption of the battery can be effectively improved while ensuring the carrier collection efficiency. In this thesis, the common amorphous silicon thin-film light-trapping technology is introduced, and the surface plasmon (SP) generated on the surface of the metal nano-structure is mainly reviewed in the light of the solar cell. on the basis of which, a one-dimensional or two-dimensional periodic distribution metal nano-structure (i.e., a metal nano-grating) is introduced into the front surface or the back surface of the amorphous silicon thin-film battery, and the like, a plurality of light-trapping junctions are designed for an amorphous silicon thin-film battery, The paper adopts the COMSOL numerical simulation software based on the finite element method to simulate the light absorption of different light-trapping structure solar cells. By analyzing the photon absorption rate, the absorption spectrum, the distribution of the electromagnetic field in the light-absorbing layer and the scattering cross-section of the metal nano-particles, the light-trapping structure is optimized, and the light-trapping machine is described. The main research results in this paper are as follows: (1) One-dimensional Ag nano-grating is designed on the front surface of the amorphous silicon thin-film solar cell: in the case of vertical incidence of TM wave, one-dimensional Ag nano-grating in the front surface has one-dimensional Ag nano-grating, and the photon absorption rate of the cell in the short wave band is more than that of the reference cell. However, when the radius of the section of the grating is R = 50 nm and the period P = 350 nm, the total light absorption of the battery is higher than that of the reference cell. 5%. However, under the incidence of TE wave, the surface plasmon can not be generated on the surface of the Ag grating, and the Ag grating itself has a certain absorption and reflection on the incident light, so that the number of photons absorbed in the whole incident light spectrum (300-800 nm) is only the reference cell when the mixed wave is incident. 92%. That is, after the one-dimensional Ag nano-grating is introduced on the front surface, the light absorption of the amorphous silicon thin-film solar cell Based on the above simulation results, we believe that one-dimensional metal nano-grating is not suitable to be placed in the cell in the light-trapping design of the solar cell (2) The design and optimization of the composite light trapping structure: a one-dimensional metal nano-grating is prepared between the Ag back electrode and the silicon thin film, and the anti-reflection film of the texture is deposited on the front surface of the battery by a conformal growth, The light trapping effect of the grating with the filling factor of FF = 0.5 is better than that of the grating of FF = 1 when the cross section of the one-dimensional metal nano-grating of the back surface is triangular, and the Ag grating is compared with the Al grating. The effect is better. When the top angle of the cross-section of the grating is n = 80 擄 and the area S = 18750 nm2, the total light absorption under the vertical incidence of the solar spectrum of the AM1.5 is 96% higher than that of the reference cell. When the cross section of the one-dimensional Ag nano-grating on the back surface is rectangular, the height of the rectangle is H = 90 nm, the width W = 180 nm, and the period of the grating is P = 6. at 00 nm, Eabs is the maximum the light absorption of the amorphous silicon thin-film battery can be improved in a wide spectrum range, The contribution of the texture, while the increase of the long-band photon absorption rate is the same as the surface plasmon and waveguide mode of the Ag nano-grating. in addition, the structure of the composite light trapping structure also greatly improves the incident angle of the solar light of the amorphous silicon thin film battery, and (3) the influence of the periodically distributed Ag nano-particles on the light absorption of the amorphous silicon thin-film battery: when the Ag nano-particles are arranged on the front surface of the battery, the photon absorption rate of the battery in the middle long wave section is higher than that of the reference battery under the plane wave vertical incidence; The results show that, when the radius R of the Ag nano-particles is 110 nm and the period P is 500 nm, the effect of the large particles in the large distribution period is better. at the same position of the front and rear surfaces of the battery, the Eabs of the battery It can be raised to 55%. However, the light-trapping structure cell is sensitive to the angle of incident light, and a good light-trapping effect shall be obtained, and the incident angle shall be maintained.
【學(xué)位授予單位】：鄭州大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2014
【分類號】：TM914.41
本文編號：2508929
[Abstract]:Compared with the first-generation crystalline silicon solar cell, the amorphous silicon thin-film solar cell has the advantages of saving raw materials, simple preparation process, low cost and the like. However, because the defect state density of the thin film material is high, the thick amorphous silicon layer can absorb the incident light well, but the recombination and the collector efficiency of the carriers are reduced, and therefore, the thickness of the light absorbing layer of the battery is generally required to be less than the effective diffusion length of the minority carriers; And the over-thin amorphous silicon layer obviously cannot fully absorb the incident light, especially the absorption rate of the light in the vicinity of the band gap is low, and the short-circuit current and the photoelectric conversion efficiency of the battery are also limited. In order to solve the above-mentioned contradiction, it is necessary to design an effective light-trapping structure for the battery, greatly increase the optical thickness of the light-absorbing layer of the battery under the condition that the physical thickness of the light-absorbing layer of the battery is not changed, and the light absorption of the battery can be effectively improved while ensuring the carrier collection efficiency. In this thesis, the common amorphous silicon thin-film light-trapping technology is introduced, and the surface plasmon (SP) generated on the surface of the metal nano-structure is mainly reviewed in the light of the solar cell. on the basis of which, a one-dimensional or two-dimensional periodic distribution metal nano-structure (i.e., a metal nano-grating) is introduced into the front surface or the back surface of the amorphous silicon thin-film battery, and the like, a plurality of light-trapping junctions are designed for an amorphous silicon thin-film battery, The paper adopts the COMSOL numerical simulation software based on the finite element method to simulate the light absorption of different light-trapping structure solar cells. By analyzing the photon absorption rate, the absorption spectrum, the distribution of the electromagnetic field in the light-absorbing layer and the scattering cross-section of the metal nano-particles, the light-trapping structure is optimized, and the light-trapping machine is described. The main research results in this paper are as follows: (1) One-dimensional Ag nano-grating is designed on the front surface of the amorphous silicon thin-film solar cell: in the case of vertical incidence of TM wave, one-dimensional Ag nano-grating in the front surface has one-dimensional Ag nano-grating, and the photon absorption rate of the cell in the short wave band is more than that of the reference cell. However, when the radius of the section of the grating is R = 50 nm and the period P = 350 nm, the total light absorption of the battery is higher than that of the reference cell. 5%. However, under the incidence of TE wave, the surface plasmon can not be generated on the surface of the Ag grating, and the Ag grating itself has a certain absorption and reflection on the incident light, so that the number of photons absorbed in the whole incident light spectrum (300-800 nm) is only the reference cell when the mixed wave is incident. 92%. That is, after the one-dimensional Ag nano-grating is introduced on the front surface, the light absorption of the amorphous silicon thin-film solar cell Based on the above simulation results, we believe that one-dimensional metal nano-grating is not suitable to be placed in the cell in the light-trapping design of the solar cell (2) The design and optimization of the composite light trapping structure: a one-dimensional metal nano-grating is prepared between the Ag back electrode and the silicon thin film, and the anti-reflection film of the texture is deposited on the front surface of the battery by a conformal growth, The light trapping effect of the grating with the filling factor of FF = 0.5 is better than that of the grating of FF = 1 when the cross section of the one-dimensional metal nano-grating of the back surface is triangular, and the Ag grating is compared with the Al grating. The effect is better. When the top angle of the cross-section of the grating is n = 80 擄 and the area S = 18750 nm2, the total light absorption under the vertical incidence of the solar spectrum of the AM1.5 is 96% higher than that of the reference cell. When the cross section of the one-dimensional Ag nano-grating on the back surface is rectangular, the height of the rectangle is H = 90 nm, the width W = 180 nm, and the period of the grating is P = 6. at 00 nm, Eabs is the maximum the light absorption of the amorphous silicon thin-film battery can be improved in a wide spectrum range, The contribution of the texture, while the increase of the long-band photon absorption rate is the same as the surface plasmon and waveguide mode of the Ag nano-grating. in addition, the structure of the composite light trapping structure also greatly improves the incident angle of the solar light of the amorphous silicon thin film battery, and (3) the influence of the periodically distributed Ag nano-particles on the light absorption of the amorphous silicon thin-film battery: when the Ag nano-particles are arranged on the front surface of the battery, the photon absorption rate of the battery in the middle long wave section is higher than that of the reference battery under the plane wave vertical incidence; The results show that, when the radius R of the Ag nano-particles is 110 nm and the period P is 500 nm, the effect of the large particles in the large distribution period is better. at the same position of the front and rear surfaces of the battery, the Eabs of the battery It can be raised to 55%. However, the light-trapping structure cell is sensitive to the angle of incident light, and a good light-trapping effect shall be obtained, and the incident angle shall be maintained.
【學(xué)位授予單位】：鄭州大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2014
【分類號】：TM914.41
【參考文獻】
相關(guān)期刊論文 前2條
1 沈宏君;盧輝東;程學(xué)珍;;一維衍射光柵和一維光子晶體組成的硅薄膜太陽能電池背反射器[J];發(fā)光學(xué)報;2012年06期
2 明海;王小蕾;王沛;魯擁;;表面等離激元的調(diào)控研究與應(yīng)用[J];科學(xué)通報;2010年21期
本文編號：2508929
本文鏈接：http://sikaile.net/kejilunwen/dianlilw/2508929.html
最近更新
教材專著
