We are interested in miscut silicon, which works as zero-background substrates for our nanocrystals (we typically drop onto the silicon) we have 4" silicon (111) oriented, 7deg off toward the (110). We would need a quotation of the same kind of silicon wafer, or similar alternatives.
Substrates Used for Nanocrystal Applications
Zero-Background Wafers for Nanocrystals
A PhD candidate requested a quote for the following.
Reference #133213 for specs and pricing.
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Wafers Used for Colloidal Nanocrystal Sensitized Photovoltaic Cells Fabrication
A postdoc requested a quote for the following.
I have been purchasing my Graphene from the same company for a while now, their good, I like that there has never been a problem. I am ordering something a little different for my upcoming research and I thought I should shop around for a better price this time, my store must not like the idea. The substrate I wish to have you guys put Graphene on is a very thin (0.1mm-0.2mm), very stout plastic circle. It is what is used to make buttons.
I wish to have graphene on both sides as shown in the crude schematic I sent. They will be off-center to avoid touching one another and the substrates will be sent to you with the notches in them as well as a more respectable schematic. I would also like Raman spectrophotometry if at all possible as well as the state of Graphene ( as in if it will have coating, what it is to be transferred in, and any other information I can receive). Thank you very much for your time.
I would send the substrate with schematic and notches for desired placement. Did I answer what was pondered in my general direction? There was some awesome backslash action in the message and I may have missed the message. I like it though, it makes me feel like I am not as well versed in the measure... consequently, I desire the backslash lyrics in my e-mail songs. I do have relativistic properties at room temperature, so I got that goin for me.
The substrate was chosen from the need of translucence. If their is something else that would hold Graphene on either side that might just work out better. I am concerned about sealing and getting conductivity from outside the seal to inside. I am making colloidal nanocrystal sensitized photovoltaic cells and, presently, taking the risk of failure of the previous concept in place of introducing more chemicals into the mix. I love my research being red-flagged by spellcheck. Front line.
Reference #220711 for specs and pricing.
Quantum Dots, Such as Colloidal Semiconductor Nanocrystals
A technological development engineer requested a quote for the following.
I need a quotation for 25 pcs of silicon wafer with ID 1317 ( Diam. 1000um, type P, orientation <100>, SSP, Prime ).
Besides these silicon wafers, I need glass wafer with a refractive index ranging from 1.7 to 2, with a thickness of about 600um - 1000um. I would like these glass wafer to have the best transmissibility in a wider range of wavelengths.
I understand that you offer small wafer quantities?
If you could help me with such glass plates that would sadisse my optical properties, I would be grateful.
We have partnered with a manufacturer of Quantum dots used for various applications in industries and R&D.
A quantum dot is a semiconductor nanostructure
that confines the motion of conduction band electrons, valence band holes or excitons in all three spatial directions. These semiconductor materials can be made from an element, such as silicon or germanium, or a compound, such as CdS or CdSe. These tiny particles can differ in color depending on their size.
Small quantum dots, such as colloidal semiconductor nanocrystals, can be as small as 2 to 10 nanometers, corresponding to 10 to 50 atoms in diameter and a total of 100 to 100,000 atoms within the quantum dot volume.Self-assembled quantum dots are typically between 10 and 50 nm in size.Quantum dots defined by lithographically patterned gate electrodes or by etching on two-dimensional electron gases in semiconductor heterostructures can have lateral dimensions exceeding 100 nm.
For the 25 pieces of silicon wafers you could also send me an invoice in order to make the payment by bank transfer?
Reference #228532 for specs and pricing.
Lithography and Optical Microscopy on Nanocrystals
A physical chemistry researcher requested a quote for the following.
I work at a university physical chemistry lab. We are looking for optical grade 3-4 inch ultra thin glass and sapphire wafers for single particle spectroscopy, on which we grow Al2O3 and aluminum and do mask lithography, we need a thickness between 140-175 microns for the optical objective working distance. We are currently using Borofloat n.1 cover slides. If you have any of these options we would be happy to test them and get a quote for an initial order.
The application is lithography and optical microscopy on nanocrystals. The wafers need to be optical grade double side polished (use with a transmission confocal microscope with a 100x objective and 0.16mm working distance).
Regarding quantity- we will need to start with the minimal amount (5-10) for tests, later i believe we will buy 25-50 per year.
Regarding the glass type- we used borofloat up to now, but i would like to hear about options of fused silica, quartz, and sapphire if possible (the substrates later go under a TEM microscope and we have some truble with the borofloat glass at high electron beam energy).
Reference #262853 for specs and pricing.
What Substrates and specs are most often Used for Nanocrystal Applications?
For nanocrystal applications, the choice of substrate depends on the specific requirements of the nanocrystal system, including growth, stability, and optical/electrical properties. Here are the most commonly used substrates along with their key specifications:
1. Silicon (Si)
- Crystal Orientation: <100>, <111>
- Doping: Intrinsic, p-type (Boron), or n-type (Phosphorus/Arsenic)
- Surface: Single-side polished (SSP) or double-side polished (DSP)
- Oxide Layer: Often thermally grown SiO₂ for controlled surface chemistry
- Application: Used when electrical integration is needed or for CMOS compatibility.
2. Silicon Dioxide (SiO₂) on Si
- Thermal Oxide Thickness: Typically 100 nm – 1 µm
- Purpose: Provides an insulating layer to control charge interactions between nanocrystals and the substrate.
3. Silicon-on-Insulator (SOI)
- Top Silicon Thickness: 10 nm – 300 nm
- Buried Oxide (BOX) Thickness: 50 nm – 3 µm
- Application: High-performance electronic devices using nanocrystals for sensing or transistor structures.
4. Sapphire (Al₂O₃)
- Crystal Orientation: c-plane (0001), a-plane (11-20), r-plane (1-102)
- Advantage: High thermal stability, good transparency for optical applications, and lattice matching for III-V semiconductors.
- Application: Used in optoelectronic devices, such as quantum dots or nanocrystal lasers.
5. Fused Quartz
- Surface Roughness: Ultra-flat (<0.5 nm RMS)
- Advantage: Transparent in UV and visible ranges, useful for optical nanocrystals.
- Application: Used for spectroscopy, photonics, and luminescent nanocrystal studies.
6. Glass (Borosilicate or Quartz)
- Advantages: Cost-effective, high optical transparency, non-conductive.
- Application: Used in bioimaging and optoelectronic nanocrystal applications.
7. Metal-Coated Substrates (Au, Ag, Pt)
- Thickness: 10 nm – 100 nm of metal on Si or glass
- Function: Enables plasmonic interactions, catalytic effects, or surface-enhanced Raman spectroscopy (SERS) with nanocrystals.
8. Graphene and 2D Materials (e.g., MoS₂, h-BN)
- Structure: Monolayer or few-layer films on SiO₂ or quartz
- Advantage: High electron mobility, tunable band structure.
- Application: Used for energy storage, sensing, and quantum dot applications.
9. Polymer Coated Substrates (e.g., PMMA, PDMS)
- Function: Flexible substrates for soft electronics.
- Application: Nanocrystal-based flexible optoelectronics and bioelectronics.
10. Indium Tin Oxide (ITO) on Glass or Si
- Sheet Resistance: 10 – 100 Ω/sq
- Application: Transparent conducting layer for photovoltaic nanocrystal applications.
Would you like recommendations based on specific nanocrystal materials (e.g., quantum dots, perovskites, etc.)?
Undoped Silicon Wafers for FTIR Analysis of Nanocrystals
A graduate student requested a quote for the following.
For my research, I need to conduct FTIR analysis of nanocrystals. For that, I need double-sided polished undoped Si wafers with a ~650–750 µm thickness. As a starting point, I need to purchase a pack of 5 Si wafers, whether they work or not. Could you please provide me with a quote for it. Your earliest attention would be greatly appreciated.
Reference #318502 for specs and pricing.
What Are Colloidal Semiconductor Nanocrystals?
Colloidal semiconductor nanocrystals (also known as quantum dots) are nanoscale semiconductor particles that are synthesized and stabilized in a liquid medium (colloidal solution). These nanocrystals exhibit size-dependent quantum confinement effects, meaning their electronic and optical properties can be tuned by simply adjusting their size, shape, and composition.
Key Features of Colloidal Semiconductor Nanocrystals
- Quantum Confinement Effect: Their bandgap and optical properties change with size, allowing for tunable emission wavelengths.
- High Photoluminescence Efficiency: Strong light absorption and emission make them ideal for optoelectronics.
- Solution Processability: They can be easily integrated into devices using simple deposition techniques.
- High Stability: Can be engineered for long-term stability in different environments.
Applications of Colloidal Semiconductor Nanocrystals
1. Optoelectronic Devices
- Quantum Dot LEDs (QLEDs): Used in next-generation display technologies for high-resolution, high-efficiency televisions and monitors.
- Photodetectors: Enable ultra-sensitive light detection for cameras, biomedical imaging, and night vision applications.
- Lasers: Used in nanoscale laser technology due to their tunable emission properties.
2. Photovoltaics and Energy Harvesting
- Quantum Dot Solar Cells (QDSCs): Improve light absorption efficiency by harvesting energy across a wider spectrum compared to traditional silicon solar cells.
- Thermoelectric Energy Conversion: Nanocrystals can enhance heat-to-electricity conversion by reducing thermal conductivity.
3. Biomedical Imaging and Biosensing
- Fluorescent Biological Labels: Used for biological imaging, targeting cancer cells, and tracking cellular interactions.
- Biosensors: Functionalized nanocrystals can be used for rapid disease detection through fluorescence-based sensing techniques.
4. Quantum Computing and Information Storage
- Single-Photon Emitters: Quantum dots serve as controlled sources of single photons for quantum cryptography and quantum computing applications.
- Optical Memory Devices: Used in high-density data storage systems.
5. Catalysis and Environmental Applications
- Photocatalysis: Used for water splitting (hydrogen production) and pollutant degradation under light exposure.
- CO₂ Reduction: Convert carbon dioxide into valuable hydrocarbons through light-driven catalytic reactions.
Material Recommendations for Colloidal Semiconductor Nanocrystals
Different materials offer unique properties for various applications. Here’s a breakdown of the most commonly used colloidal semiconductor nanocrystals and their best-suited applications:
1. Cadmium Selenide (CdSe) Nanocrystals
🔹 Key Features:
- Strong size-dependent photoluminescence (emits in the visible spectrum).
- High quantum yield (~80-90%).
- Tunable emission from blue to red (450-650 nm) by controlling the nanocrystal size.
- Commonly capped with ZnS for improved stability.
🔹 Best Applications:
✔ Quantum Dot LEDs (QLEDs) – Used in high-quality TV and display panels (Samsung QLEDs, for example).
✔ Fluorescent Biological Labels – CdSe/ZnS core-shell QDs are widely used in biomedical imaging and diagnostics.
✔ Photodetectors & Sensors – High absorption makes them suitable for light-sensitive devices.
🔸 Limitations: Contains cadmium, a toxic heavy metal, leading to environmental concerns and regulatory restrictions.
2. Lead Sulfide (PbS) and Lead Selenide (PbSe) Nanocrystals
🔹 Key Features:
- Infrared (IR) absorption & emission (PbS: 900-1600 nm, PbSe: up to 2500 nm).
- High carrier mobility, making them great for optoelectronics.
- Strong two-photon absorption for non-linear optics.
🔹 Best Applications:
✔ Infrared Photodetectors & Night Vision – Used in security cameras, medical imaging, and military applications.
✔ Telecommunications – Infrared optical communication (fiber optics).
✔ Quantum Dot Solar Cells (QDSCs) – PbS QDs improve near-infrared light harvesting in next-gen solar cells.
✔ Thermoelectric Devices – Used for waste-heat-to-electricity conversion.
🔸 Limitations: Pb-based materials also pose toxicity concerns.
3. Perovskite Nanocrystals (CsPbX₃, where X = Cl, Br, I)
🔹 Key Features:
- Exceptional photoluminescence quantum yield (~95%).
- Tunable emission from UV to near-infrared (400-800 nm).
- Fast carrier recombination time, enabling high-speed optoelectronics.
- Lower synthesis cost compared to CdSe and PbS.
🔹 Best Applications:
✔ Perovskite Quantum Dot LEDs (PQDs) – Bright and efficient light emission for display technologies.
✔ Quantum Dot Solar Cells (Perovskite-Si tandem cells) – Can surpass 30% efficiency.
✔ Single-Photon Emitters & Quantum Computing – Suitable for future quantum information technologies.
🔸 Limitations: Stability is an issue – prone to degradation in moisture, oxygen, and heat. Encapsulation techniques are needed for commercial applications.
4. Indium Phosphide (InP) Nanocrystals (Cadmium-Free Alternative)
🔹 Key Features:
- Non-toxic alternative to Cd-based nanocrystals.
- Strong optical absorption and emission from visible to near-IR.
- Approved for use in commercial electronics due to RoHS compliance.
🔹 Best Applications:
✔ Cadmium-Free QLED Displays – Used in Samsung and LG TVs.
✔ Biocompatible Fluorescent Labels – Suitable for medical diagnostics and imaging.
✔ Photodetectors & IR Sensors – Efficient for near-infrared detection applications.
🔸 Limitations: Lower quantum yield and stability than CdSe/ZnS quantum dots, but improving with better synthesis methods.
5. Zinc Oxide (ZnO) and Copper Indium Sulfide (CIS) Nanocrystals (Eco-Friendly Options)
🔹 Key Features:
- ZnO: High electron mobility, excellent UV absorption.
- CIS: Cadmium-free, strong photoluminescence, but lower quantum efficiency than CdSe.
🔹 Best Applications:
✔ UV Sensors & Photodetectors (ZnO QDs).
✔ Eco-Friendly Solar Cells & LEDs (CIS QDs, ZnO QDs).
✔ Biomedical Imaging & Theranostics (CIS QDs, ZnO QDs are less toxic than CdSe-based QDs).
🔸 Limitations: CIS QDs have lower efficiency, and ZnO QDs need surface modifications for stability.
Final Recommendations Based on Your Application Needs
| Application | Recommended Nanocrystal |
|---|---|
| High-Resolution Displays (QLEDs) | CdSe/ZnS (if allowed), Perovskite QDs, InP QDs |
| Infrared Sensing & Photodetectors | PbS, PbSe, InP |
| Quantum Dot Solar Cells (QDSCs) | Perovskite QDs, PbS QDs, CIS QDs |
| Biomedical Imaging & Biosensing | CdSe/ZnS (for fluorescence), CIS QDs, InP QDs |
| Quantum Computing & Single-Photon Emitters | Perovskite QDs, PbS QDs |
| Thermoelectrics & Energy Harvesting | PbS QDs, ZnO QDs |
Would you like supplier recommendations or synthesis protocols for any of these nanocrystals?