Invited; Epitaxy and heterostructure of germanium tin-related group-IV alloy semiconductors for future electronic and optoelectronic applications

GeSn and related group-IV alloys have been much attracted as one of novel semiconductor materials for nextgeneration nanoelectronics, optoelectronics, and thermoelectronics applications. GeSn semiconductor promises high carrier mobility, highly efficient optoelectronic conversion, low thermal conductivity, and also low thermal budget process those properties are appropriate for the integration on Si ULSI platform. On the other hand, there are some challenges for practical applications of GeSn thin films integrating into Si ULSI. One is realizing a high substitutional Sn content over several percents in GeSn and related alloys, since the thermal equilibrium solid-solubility of Sn in Ge is as low as 1% (0.1% in the case of Si). In addition, the strain control of GeSn heteroepitaxial layers with a high crystalline quality is required for energy band engineering. Thus, it is necessary to understand and establish the crystal growth science and technology of GeSn-related group-IV thin films to control those crystalline and electronic properties. Please click Download on the upper right corner to see the full abstract

Growth and applications of GeSn-related group-IV semiconductor materials

We review the technology of Ge1−xSnx-related group-IV semiconductor materials for developing Si-based nanoelectronics. Ge1−xSnx-related materials provide novel engineering of the crystal growth, strain structure, and energy band alignment for realising various applications not only in electronics, but also in optoelectronics. We introduce our recent achievements in the crystal growth of Ge1−xSnx-related material thin films and the studies of the electronic properties of thin films, metals/Ge1−xSnx, and insulators/Ge1−xSnx interfaces. We also review recent studies related to the crystal growth, energy band engineering, and device applications of Ge1−xSnx-related materials, as well as the reported performances of electronic devices using Ge1−xSnx related materials

How to Encrypt Long Messages without Large Size Symmetric/Asymmetric Encryption Schemes

. Suppose that we wish to encrypt long messages with small overhead by a public key encryption scheme which is secure against adaptive chosen ciphertext attack (IND-CCA2). Then the previous schemes require either a large size one-way trapdoor permutation (OAEP) or both a large size symmetric encryption scheme and a small size asymmetric encryption scheme (hybrid encryption). In this paper, we show a scheme which requires only a small size asymmetric encryption scheme satisfying IND-CCA2 for our purpose. Therefore, the proposed scheme is very efficient. A hash function and a psuedorandom bit generator are used as random oracles

Public Key Cryptosystem Using A Reciprocal Number With The Same Intractability As Factoring A Large Number

This paper proposes a public key cryptosystem using a reciprocal number. Breaking the proposed cryptosystem is proven to be as difficult as factoring a large number. Encryption requires O(n 2 ) bit operations and decryption requires O(n 3 ) bit operations. (n is the bit length of a plaintext.) 1 Introduction A public key cryptosystem proposed by Rabin [1] is excellent because it has been proven that breaking the cryptosystem is as hard as factoring a large number. However, a ciphertext cannot be uniquely deciphered because four different plaintexts produce the same cipher. Williams [2] showed that this disadvantage can be overcome if the secret two prime numbers, p and q, are chosen such that p = q = 3 mod 4. RSA cryptosystem [3] is the most well-known public key cryptosystem. However, it is not known whether breaking RSA cryptosystem is as hard as factoring a lagre number. Recently, Williams [4] proposed a modified RSA cryptosystem which utilizes quadratic irrational numbers. He ..

A case of oral metastasis of rectal adenocarcinoma with KRAS mutation in patient with synchronous lung adenocarcinoma.

Detecting the origin of the primary cancer that metastasizes in the oral cavity in patients with multiple primary cancers is challenging because of its rarity and complexity. We present an unusual case of an 86‐year‐old women with a maxillary gingival tumor that was histologically proven to be adenocarcinoma; she had been diagnosed with rectal and lung adenocarcinoma. A multidisciplinary approach involving complementary molecular analysis of KRAS gene mutation helped in the diagnosis of metastatic gingival tumor from rectal cancer