单室沉积非晶硅/非晶硅/微晶硅三叠层太阳电池的研究

在产业化比较成熟的单室沉积非晶硅薄膜太阳电池基础上,进行了非晶硅/非晶硅/微晶硅三叠层太阳电池性能优化的研究.在生产线上纯单室沉积的非晶硅/非晶硅叠层太阳电池基础上,通过调节n-p隧穿结并采用自行研制开发的单室微晶硅底电池的沉积路线,获得了单室沉积的光电转换效率达到9.52%的非晶硅/非晶硅/微晶硅三叠层太阳电池. 关键词： 硅基薄膜太阳电池 三叠层 微晶硅     

单室沉积p-i-n型微晶硅薄膜太阳电池性能优化的研究

采用原位的氢等离子体处理技术和微晶覆盖技术来降低单室沉积p-i-n型微晶硅薄膜太阳电池中的硼污染问题.通过对不同处理技术所制备电池的电流密度-电压和量子效率测试结果的比较发现,一定的氢处理时间和合适的覆盖层技术都可以在一定程度上提高电池的性能,但每种方法的影响程度各异、文中对此异同进行了分析.通过对电池陷光结构和氢等离子体处理时间的优化,在单室中获得了效率为6.39%的单结微晶硅太阳电池.     

提高非晶硅/微晶硅叠层太阳电池光稳定性的研究

如何提高硅基薄膜太阳电池的光稳定性是硅基薄膜太阳电池研究和产业化过程中非常重要的问题. 为了提高非晶硅/微晶硅叠层电池的光稳定性, 本文首先给出了良好光稳定性非晶硅顶电池的结果, 然后重点研究了N/P隧穿结和微晶硅底电池本征层硅烷浓度梯度对叠层电池光稳定性的影响. 经过初步优化, 连续光照1000 h后非晶硅/微晶硅叠层电池的最小光致衰退率只有7%.     

微纳结构提高晶硅太阳电池的辐射散热

太阳能电池受阳光照射发电同时产生热量引起温度升高,但温度的升高对其效率和可靠性都有不利影响。本文引入一种辐射散热的方法,通过辐射将热量散发到外层空间来降低太阳电池的工作温度。本文提出一种微纳结构应用于晶硅太阳电池的设计,在8～13μm大气窗口范围内提高太阳电池的发射率,进而提高太阳电池的辐射散热能力,使太阳电池的温度降低。该结构由如下几个部分组成:Si_3N_4层,SiO_2层,Si层。理论分析表明,与顶部采用Si3N_4薄膜层太阳电池以及无薄膜层的晶硅电池相比,采用Si_3N_4和SiO_2层交替薄膜结构的发射率有大幅提高;针对Si_3N_4和SiO_2层交替薄膜结构,分析了结构中各层厚度对晶硅电池发射率的影响。     

微晶硅锗薄膜作为近红外光吸收层在硅基薄膜太阳电池中的应用

采用射频等离子体增强化学气相沉积技术,制备了具有一定晶化率不同Ge含量的氢化微晶硅锗(μcSi1-xGex:H)薄膜.通过Ⅹ射线荧光谱、拉曼光谱、X射线衍射谱、傅里叶红外谱、吸收系数谱和电导率的测试,表征了μc-Si_(1-x)Ge_x:H的材料微结构随Ge含量的演变.研究表明:提高Ge含量可以增强μc-Si_(1-x)Ge_x:H薄膜的吸收系数.将其应用到硅基薄膜太阳电池的本征层中可以有效提高电池的短路电流密度(J_(sc)).特别是在电池厚度较薄或陷光不充分的情况下,长波响应的提高会更为显著.应用ZnO衬底后,在Ge含量分别为9%和27%时,μc-Si_(1-x)Ge_x:H太阳电池的转换效率均超过了7%.最后,将μc-Si_(1-x)Ge_x:H太阳电池应用在双结叠层太阳电池的底电池中,发现μc-Si_(0.73)Ge_(0.27):H底电池在厚度为800 nm时即可得到比1700 nm厚微晶硅(μc-Si:H)底电池更高的长波响应.以上结果体现μc-Si_(1-x)Ge_x:H太阳电池作为高效近红外光吸收层,在硅基薄膜太阳电池中应用的前景.     

甚高频等离子体增强化学气相沉积制备微晶硅太阳电池的研究

采用甚高频等离子体增强化学气相沉积技术成功地制备了不同硅烷浓度和辉光功率条件下的微晶硅电池.电池的J-V测试结果表明：在实验的硅烷浓度和功率范围内，随硅烷浓度的降低和功率的加大，对应电池的开路电压逐渐变小；硅烷浓度的不同对电池的短路电流密 度有很大的影响，但功率的影响在实验研究的范围内不是很显著.对于微晶硅电池，N层最好 是非晶硅，这是因为一方面可以降低对电流的横向收集效应，另一方面也降低了电池的漏电概率，提高了电池的填充因子. 关键词： 微晶硅太阳电池 甚高频等离子体增强化学气相沉积     

高氢稀释制备微晶硅薄膜微结构的研究

采用高氢稀硅烷热丝化学气相沉积方法制备氢化微晶硅薄膜.其结构特征用Raman谱，红外透射谱，小角X射线散射等来表征.结果表明微晶硅的大小及在薄膜中的晶态比χ_c随氢稀释度的提高而增加.而从红外谱计算得到氢含量则随氢稀释度的增加而减少.小角X射线散射结果表明薄膜致密度随氢稀释度的增加而增加.结合红外谱和小角X射线散射的结果讨论与比较了不同相结构下硅网络中H的键合状态.认为随着晶化的发生和晶化程度的提高H逐渐移向晶粒表面，在硅薄膜中H的存在形式从以SiH为主向SiH₂ 关键词：     

超薄高速率单结微晶硅薄膜电池及其叠层电池

采用甚高频等离子体增强化学气相沉积技术, 基于优化表面形貌及光电特性的溅射后腐蚀ZnO:Al衬底, 将通过调控工艺参数获得的器件质量级高速微晶硅(μupc-Si:H )材料(沉积速率达10.57 Å/s)应用到微晶硅单结电池中, 获得了初始效率达7.49%的高速率超薄微晶硅单结太阳电池(本征层厚度为1.1 μm). 并提出插入n型微晶硅和p型微晶硅的隧穿复合结, 实现了非晶硅顶电池和微晶硅底电池之间的低损电连接, 由此获得了初始效率高达12.03% (V_oc=1.48 eV, J_sc=11.67 mA/cm², FF=69.59%)的非晶硅/微晶硅超薄双结叠层电池(总厚度为1.48 μm), 为实现低成本生产太阳电池奠定了基础.     

甚高频高速沉积微晶硅薄膜的研究

采用甚高频化学气相沉积(VHF-PECVD)技术制备了系列微晶硅(μc-Si:H)薄膜样品,重点研究了硅烷浓度、功率密度、沉积气压和气体总流量对薄膜沉积速率和结晶状态的影响,绘制了沉积气压和功率密度双因素相图. 以0.75nm/s的高速沉积了器件质量级的微晶硅薄膜,并以该沉积速率制备出了效率为5.5%的单结微晶硅薄膜电池. 关键词： 微晶硅薄膜 高速沉积 甚高频化学气相沉积     

微晶硅n-i-p太阳电池中n型掺杂层对本征层结构特性的影响

采用高压射频等离子体增强化学气相沉积方法在非晶和微晶两种n型硅薄膜衬底上沉积了一系列不同厚度的本征微晶硅薄膜,研究了不同n型硅薄膜对本征微晶硅薄膜的表面形貌、晶化率和结晶取向等结构特性的影响.结果表明,本征微晶硅薄膜结构对n型掺杂层具有强烈的依赖作用,微晶n型掺杂层能够有效减少n/i界面非晶孵化层的厚度,改善本征微晶硅薄膜的纵向均匀性,进而提高微晶硅n-i-p太阳电池性能. 关键词： 孵化层 微晶硅薄膜 纵向均匀性 n-i-p太阳电池     

微晶硅薄膜晶体管稳定性研究

对有源区处于结构过渡区的微晶硅底栅薄膜晶体管，测试其偏压衰退特性时，观察到一种“自恢复”的衰退现象.当栅和源漏同时施加10 V的偏压时，测试其源-漏电流随时间的变化，发现源-漏电流先衰减、而后又开始恢复上升的反常现象.而当采用栅压为10 V、源-漏之间施加零偏压的模式时，源-漏电流随时间呈先是几乎指数式下降、随之是衰退速度减缓的正常衰退趋势.就此现象进行了初步探讨. 关键词： 过渡区硅材料 微晶硅薄膜晶体管 稳定性 自恢复衰退     

Influence of the total gas flow rate on high rate growth microcrystalline silicon films and solar cells

This paper reports that high-rate-deposition of microcrystalline silicon solar cells was performed by very-high-frequency plasma-enhanced chemical vapor deposition. These solar cells, whose intrinsic μ c-Si:H layers were prepared by using a different total gas flow rate (F_total), behave much differently in performance, although their intrinsic layers have similar crystalline volume fraction, opto-electronic properties and a deposition rate of ～ 1.0~nm/s. The influence of F_total on the micro-structural properties was analyzed by Raman and Fourier transformed infrared measurements. The results showed that the vertical uniformity and the compact degree of μ c-Si:H thin films were improved with increasing F_total. The variation of the microstructure was regarded as the main reason for the difference of the J--V parameters. Combined with optical emission spectroscopy, we found that the gas temperature plays an important role in determining the microstructure of thin films. With F_total of 300~sccm, a conversion efficiency of 8.11% has been obtained for the intrinsic layer deposited at 8.5~\AA/s (1~\AA=0.1\,nm).     

The effect of initial discharge conditions on the properties of microcrystalline silicon thin films and solar cells

This paper studies the effects of silane back diffusion in the initial plasma ignition stage on the properties of microcrystalline silicon ($\mu $c-Si:H) films by Raman spectroscopy and spectroscopic ellipsometry, through delaying the injection of SiH7280N, 7830G, 8115Hhttp://cpb.iphy.ac.cn/CN/10.1088/1674-1056/19/5/057205https://cpb.iphy.ac.cn/CN/article/downloadArticleFile.do?attachType=PDF&id=111771back diffusion, microcrystalline silicon, thin film, Raman crystallinityProject supported by the State Key Development Program for Basic Research of China (Grant No.~2006CB202601).This paper studies the effects of silane back diffusion in the initial plasma ignition stage on the properties of microcrystalline silicon ($\mu $c-Si:H) films by Raman spectroscopy and spectroscopic ellipsometry, through delaying the injection of SiH$_{4}$ gas to the reactor before plasma ignition. By comparing with standard discharge condition, delayed SiH$_{4}$ gas condition could prevent the back diffusion of SiH$_{4}$ from the reactor to the deposition region effectively, which induced the formation of a thick amorphous incubation layer in the interface between bulk film and glass substrate. Applying this method, it obtains the improvement of spectral response in the middle and long wavelength region by combining this method with solar cell fabrication. Finally, results are explained by modifying zero-order analytical model, and a good agreement is found between model and experiments concerning the optimum delayed injection time.back;diffusion;microcrystalline;silicon;thin;film;Raman;crystallinityThis paper studies the effects of silane back diffusion in the initial plasma ignition stage on the properties of microcrystalline silicon(μc-Si:H) films by Raman spectroscopy and spectroscopic ellipsometry,through delaying the injection of SiH4 gas to the reactor before plasma ignition.Compared with standard discharge condition,delayed SiH4 gas condition could prevent the back diffusion of SiH4 from the reactor to the deposition region effectively,which induced the formation of a thick amorphous incubation layer in the interface between bulk film and glass substrate.Applying this method,it obtains the improvement of spectral response in the middle and long wavelength region by combining this method with solar cell fabrication.Finally,results are explained by modifying zero-order analytical model,and a good agreement is found between the model and experiments concerning the optimum delayed injection time.     

Unlinking absorption and haze in thin film silicon solar cells front electrodes

We study the respective influence of haze and free carrier absorption (FCA) of transparent front electrodes on the photogenerated current of micromorph thin film silicon solar cells. To decouple the haze and FCA we develop bi‐layer front electrodes: a flat indium tin oxide layer assures conduction and allows us to tune FCA while the haze is adjusted by varying the thickness of a highly transparent rough ZnO layer. We show how a minimum amount of FCA leads only to a few percents absorption for a single light path but to a strong reduction of the cell current in the infrared part of the spectrum. Conversely, a current enhancement is shown with increasing front electrode haze up to a saturation of the current gain. This saturation correlates remarkably well with the haze of the front electrode calculated in silicon. This allows us to clarify the requirements for the front electrodes of micromorph cells. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

太阳电池用本征微晶硅材料的制备及其结构研究

采用VHF-PECVD技术制备了系列不同硅烷浓度和反应气压的微晶硅薄膜.运用拉曼散射光谱和 x射线衍射对制备的材料进行了结构分析.在实验研究的范围内，制备材料的晶化程度随硅烷 浓度的增加而降低.XRD的测试结果表明：制备的微晶硅材料均体现了(220)方向择优.应用在 电池的有源层中，制备出了效率达7.1%的单结微晶硅太阳电池，电池的结构是glass/ZnO/p( μc-Si:H)/i(μc-Si:H)/n(a-Si:H/Al)，没有ZnO背反射电极，有源层的厚度仅为1.2μm. 关键词： 本征微晶硅薄膜 拉曼光谱 x射线衍射     

单室沉积高效非晶硅/微晶硅叠层太阳电池的研究

采用甚高频等离子体增强化学气相沉积技术,在前期单室沉积的微晶硅薄膜太阳电池和非晶硅/微晶硅叠层太阳电池研究的基础上,通过对微晶硅底电池本征层硅烷浓度的优化,获得了初始效率达到11.02%(电池面积1.0 cm²)的非晶硅/微晶硅叠层太阳电池.同时,100 cm²的非晶硅/微晶硅叠层太阳电池的组件效率也达到了9.04%. 关键词： 非晶硅/微晶硅叠层电池 单室 甚高频     

Optimized emitter contacting on multicrystalline silicon thin film solar cells

We present an optimized contacting scheme for multicrystalline silicon thin film solar cells on glass based on epitaxially crystallized emitters with a thin Al₂O₃ layer and a silver back reflector. In a first step a 6.5 µm thick amorphous silicon absorber layer is crystallized by a diode laser. In a second step a thin silicon emitter layer is epitaxially crystallized by an excimer laser. The emitter is covered by an Al₂O₃ layer with a thickness ranging from 1.0 nm to 2.5 nm, which passivates the surface and acts as a tunnel barrier. On top of the Al₂O₃ layer a 90–100 nm thick silver back reflector is deposited. The Al₂O₃ layer was found to have an optimal thickness of 1.5 nm resulting in solar cells with back reflector that achieve a maximum open‐circuit voltage of 567 mV, a short‐circuit current density of 27.9 mA/cm², and an efficiency of 10.9%. (© 2015 WILEY‐VCH Verlag GmbH &Co. KGaA, Weinheim)     

PIN型和NIP型硅薄膜太阳电池中绒面陷光结构和陷光性能研究

对于硅薄膜太阳电池来说, 无论是PIN型还是NIP型太阳电池, 采用绒面陷光结构来提高入射光的有效利用率是提高太阳电池效率的重要方法之一.本文采用标度相干理论对PIN和NIP型电池的绒面结构的陷光性能进行了数值模拟. 结果表明: PIN电池中前电极和NIP电池中背电极衬底粗糙度分别为160和40 nm时可获得理想的陷光效果; 在不同粗糙度背电极衬底上制备a-SiGe:H电池发现, 使用40和61.5 nm 背电极可获得相当的短路电流密度, 理论分析和实验得到了一致的结果. 关键词： 陷光结构 光散射能力 标量相干理论 硅基薄膜太阳电池     

Fabrication and characterization of zinc oxide anti-reflective coating on flexible thin film microcrystalline silicon solar cell

This paper studies the fabrication and characterization of 80 nm zinc oxide anti-reflective coating (ARC) on flexible 1.3 μm thin film microcrystalline silicon (μc-Si) solar cell. High resolution X-ray diffraction (HR-XRD) shows a c-axis oriented ZnO (0 0 2) peak (hexagonal crystal structure) at 34.3° with full width at half maximum (FWHM) of 0.3936°. Atomic force microscope (AFM) measures high surface roughness root-mean-square (RMS) of the layer (50.76 nm) which suggests scattering of the incident light at the front surface of the solar cell. UV–vis spectrophotometer illustrates that ZnO ARC has optical transmittance of more than 80% in the visible and infra-red (IR) regions and corresponds to band gap (E_g) of 3.3 eV as derived from Tauc equation. Inclusion of ZnO ARC successfully suppresses surface reflectance from the cell to 2% (at 600 nm) due to refractive index grading between the Si and the ZnO besides quarter-wavelength (λ/4) destructive interference effect. The reduced reflectance and effective scattering effect of the incident light at the front side of the cell are believed to be the reasons why short-circuit current (I_sc) and efficiency (η) of the cell improve.